Demulsifier Compositions For Treatment Of Subterranean Formations And Produced Oil

ABSTRACT

Various embodiments disclosed relate to demulsifier compositions for treatment of subterranean formations or produced petroleum comprising an emulsion. In various embodiments, the present invention provides a method of treating a subterranean formation. The method includes placing in the subterranean formation a demulsifier composition. The demulsifier composition includes an alkanolamide surfactant that is a (C1-C50)hydrocarbyl amide having groups R1 and R2 substituted on the amide nitrogen, wherein R1 and R2 are each independently selected from the group consisting of —H, —(C1-C50)hydrocarbyl, and —(C1-C50)hydrocarbylene-OH, wherein at least one of R1 and R2 is —(C1-C50)hydrocarbylene-OH. The demulsifier composition includes an alkoxylated alcohol surfactant that is a (C1-C50)hydrocarbyl-OH having a —((C2-C3)alkylene-O)n—H group on the —OH group, wherein n is about 1 to about 100. The demulsifier composition also includes an amine-oxide surfactant. At each occurrence the (C1-C50)hydrocarbyl and (C1-C50)hydrocarbylene are substituted or unsubstituted and are independently selected.

BACKGROUND

Demulsification of oil-in-water or water-in-oil emulsions can be usefulduring a wide variety of subterranean treatment operations. For example,demulsification is important during hydraulic fracturing operationsbecause the presence of emulsions can increase the viscosity offracturing fluids or produced fluids, decreasing the effectivepermeability thereof and thus having a negative impact on the overallproduction. Emulsions present in produced petroleum fluids can requirethe use of post-production chemicals to eliminate them, which may not bea preferred solution.

BRIEF DESCRIPTION OF THE FIGURES

The drawings illustrate generally, by way of example, but not by way oflimitation, various embodiments discussed in the present document.

FIG. 1 illustrates a drilling assembly, in accordance with variousembodiments.

FIG. 2 illustrates a system or apparatus for delivering a composition toa subterranean formation, in accordance with various embodiments.

FIGS. 3A-C illustrate photographs of an emulsion break test performed ona demulsifier composition at room temperature at 1 minute (FIG. 3A), 5minutes (FIG. 3B), and at 10 minutes (FIG. 3C), in accordance withvarious embodiments.

FIGS. 4A-C illustrate photographs of an emulsion break test performed ona demulsifier composition at 93° C. at 1 minute (FIG. 4A), 5 minutes(FIG. 4B), and at 10 minutes (FIG. 4C), in accordance with variousembodiments.

FIGS. 5A-C illustrate photographs of an emulsion break test performed ona demulsifier composition at room temperature at 1 minute (FIG. 5A), 5minutes (FIG. 5B), and at 10 minutes (FIG. 5C), in accordance withvarious embodiments.

FIGS. 6A-C illustrate photographs of an emulsion break test performed ona demulsifier composition at 93° C. at 1 minute (FIG. 6A), 5 minutes(FIG. 6B), and at 10 minutes (FIG. 6C), in accordance with variousembodiments.

FIGS. 7A-C illustrate photographs of an emulsion break test performed ona demulsifier composition at room temperature at 1 minute (FIG. 7A), 5minutes (FIG. 7B), and at 10 minutes (FIG. 7C), in accordance withvarious embodiments.

FIGS. 8A-C illustrate photographs of an emulsion break test performed ona demulsifier composition at room temperature at 1 minute (FIG. 8A), 5minutes (FIG. 8B), and at 10 minutes (FIG. 8C), in accordance withvarious embodiments.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to certain embodiments of thedisclosed subject matter, examples of which are illustrated in part inthe accompanying drawings. While the disclosed subject matter will bedescribed in conjunction with the enumerated claims, it will beunderstood that the exemplified subject matter is not intended to limitthe claims to the disclosed subject matter.

In this document, values expressed in a range format should beinterpreted in a flexible manner to include not only the numericalvalues explicitly recited as the limits of the range, but also toinclude all the individual numerical values or sub-ranges encompassedwithin that range as if each numerical value and sub-range is explicitlyrecited. For example, a range of “about 0.1% to about 5%” or “about 0.1%to 5%” should be interpreted to include not just about 0.1% to about 5%,but also the individual values (e.g., 1%, 2%, 3%, and 4%) and thesub-ranges (e.g., 0.1% to 0.5%, 1.1% to 2.2%, 3.3% to 4.4%) within theindicated range. The statement “about X to Y” has the same meaning as“about X to about Y,” unless indicated otherwise. Likewise, thestatement “about X, Y, or about Z” has the same meaning as “about X,about Y, or about Z,” unless indicated otherwise.

In this document, the terms “a,” “an,” or “the” are used to include oneor more than one unless the context clearly dictates otherwise. The term“or” is used to refer to a nonexclusive “or” unless otherwise indicated.The statement “at least one of A and B” has the same meaning as “A, B,or A and B.” In addition, it is to be understood that the phraseology orterminology employed herein, and not otherwise defined, is for thepurpose of description only and not of limitation. Any use of sectionheadings is intended to aid reading of the document and is not to beinterpreted as limiting; information that is relevant to a sectionheading may occur within or outside of that particular section. A commacan be used as a delimiter or digit group separator to the left or rightof a decimal mark; for example, “0.000,1” is equivalent to “0.0001.”

In the methods described herein, the acts can be carried out in anyorder without departing from the principles of the invention, exceptwhen a temporal or operational sequence is explicitly recited.Furthermore, specified acts can be carried out concurrently unlessexplicit claim language recites that they be carried out separately. Forexample, a claimed act of doing X and a claimed act of doing Y can beconducted simultaneously within a single operation, and the resultingprocess will fall within the literal scope of the claimed process.

The term “about” as used herein can allow for a degree of variability ina value or range, for example, within 10%, within 5%, or within 1% of astated value or of a stated limit of a range, and includes the exactstated value or range.

The term “substantially” as used herein refers to a majority of, ormostly, as in at least about 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%,98%, 99%, 99.5%, 99.9%, 99.99%, or at least about 99.999% or more, or100%.

The term “organic group” as used herein refers to any carbon-containingfunctional group. Examples can include an oxygen-containing group suchas an alkoxy group, aryloxy group, aralkyloxy group, oxo(carbonyl)group; a carboxyl group including a carboxylic acid, carboxylate, and acarboxylate ester; a sulfur-containing group such as an alkyl and arylsulfide group; and other heteroatom-containing groups. Non-limitingexamples of organic groups include OR, OOR, OC(O)N(R)₂, CN, CF₃, OCF₃,R, C(O), methylenedioxy, ethylenedioxy, N(R)₂, SR, SOR, SO₂R, SO₂N(R)₂,SO₃R, C(O)R, C(O)C(O)R, C(O)CH₂C(O)R, C(S)R, C(O)OR, OC(O)R, C(O)N(R)₂,OC(O)N(R)₂, C(S)N(R)₂, (CH₂)₀₋₂N(R)C(O)R, (CH₂)₀₋₂N(R)N(R)₂,N(R)N(R)C(O)R, N(R)N(R)C(O)OR, N(R)N(R)CON(R)₂, N(R)SO₂R, N(R)SO₂N(R)₂,N(R)C(O)OR, N(R)C(O)R, N(R)C(S)R, N(R)C(O)N(R)₂, N(R)C(S)N(R)₂,N(COR)COR, N(OR)R, C(═NH)N(R)₂, C(O)N(OR)R, C(═NOR)R, and substituted orunsubstituted (C₁-C₁₀₀)hydrocarbyl, wherein R can be hydrogen (inexamples that include other carbon atoms) or a carbon-based moiety, andwherein the carbon-based moiety can itself be substituted orunsubstituted.

The term “substituted” as used herein in conjunction with a molecule oran organic group as defined herein refers to the state in which one ormore hydrogen atoms contained therein are replaced by one or morenon-hydrogen atoms. The term “functional group” or “substituent” as usedherein refers to a group that can be or is substituted onto a moleculeor onto an organic group. Examples of substituents or functional groupsinclude, but are not limited to, a halogen (e.g., F, Cl, Br, and I); anoxygen atom in groups such as hydroxy groups, alkoxy groups, aryloxygroups, aralkyloxy groups, oxo(carbonyl) groups, carboxyl groupsincluding carboxylic acids, carboxylates, and carboxylate esters; asulfur atom in groups such as thiol groups, alkyl and aryl sulfidegroups, sulfoxide groups, sulfone groups, sulfonyl groups, andsulfonamide groups; a nitrogen atom in groups such as amines, hydroxyamines, nitriles, nitro groups, N-oxides, hydrazides, azides, andenamines; and other heteroatoms in various other groups. Non-limitingexamples of substituents that can be bonded to a substituted carbon (orother) atom include F, Cl, Br, I, OR, OC(O)N(R)₂, CN, NO, NO₂, ONO₂,azido, CF₃, OCF₃, R, O (oxo), S (thiono), C(O), S(O), methylenedioxy,ethylenedioxy, N(R)₂, SR, SOR, SO₂R, SO₂N(R)₂, SO₃R, C(O)R, C(O)C(O)R,C(O)CH₂C(O)R, C(S)R, C(O)OR, OC(O)R, C(O)N(R)₂, OC(O)N(R)₂, C(S)N(R)₂,(CH₂)₀₋₂N(R)C(O)R, (CH₂)₀₋₂N(R)N(R)₂, N(R)N(R)C(O)R, N(R)N(R)C(O)OR,N(R)N(R)CON(R)₂, N(R)SO₂R, N(R)SO₂N(R)₂, N(R)C(O)OR, N(R)C(O)R,N(R)C(S)R, N(R)C(O)N(R)₂, N(R)C(S)N(R)₂, N(COR)COR, N(OR)R, C(═NH)N(R)₂,C(O)N(OR)R, and C(═NOR)R, wherein R can be hydrogen or a carbon-basedmoiety; for example, R can be hydrogen, (C₁-C₁₀₀)hydrocarbyl, alkyl,acyl, cycloalkyl, aryl, aralkyl, heterocyclyl, heteroaryl, orheteroarylalkyl; or wherein two R groups bonded to a nitrogen atom or toadjacent nitrogen atoms can together with the nitrogen atom or atomsform a heterocyclyl.

The term “alkyl” as used herein refers to straight chain and branchedalkyl groups and cycloalkyl groups having from 1 to 40 carbon atoms, 1to about 20 carbon atoms, 1 to 12 carbons or, in some embodiments, from1 to 8 carbon atoms. Examples of straight chain alkyl groups includethose with from 1 to 8 carbon atoms such as methyl, ethyl, n-propyl,n-butyl, n-pentyl, n-hexyl, n-heptyl, and n-octyl groups. Examples ofbranched alkyl groups include, but are not limited to, isopropyl,iso-butyl, sec-butyl, t-butyl, neopentyl, isopentyl, and2,2-dimethylpropyl groups. As used herein, the term “alkyl” encompassesn-alkyl, isoalkyl, and anteisoalkyl groups as well as other branchedchain forms of alkyl. Representative substituted alkyl groups can besubstituted one or more times with any of the groups listed herein, forexample, amino, hydroxy, cyano, carboxy, nitro, thio, alkoxy, andhalogen groups.

The term “alkenyl” as used herein refers to straight and branched chainand cyclic alkyl groups as defined herein, except that at least onedouble bond exists between two carbon atoms. Thus, alkenyl groups havefrom 2 to 40 carbon atoms, or 2 to about 20 carbon atoms, or 2 to 12carbon atoms or, in some embodiments, from 2 to 8 carbon atoms. Examplesinclude, but are not limited to, vinyl, —CH═CH(CH₃), —CH═C(CH₃)₂,—C(CH₃)═CH₂, —C(CH₃)═CH(CH₃), —C(CH₂CH₃)═CH₂, cyclohexenyl,cyclopentenyl, cyclohexadienyl, butadienyl, pentadienyl, and hexadienylamong others.

The term “acyl” as used herein refers to a group containing a carbonylmoiety wherein the group is bonded via the carbonyl carbon atom. Thecarbonyl carbon atom is bonded to a hydrogen forming a “formyl” group oris bonded to another carbon atom, which can be part of an alkyl, aryl,aralkyl cycloalkyl, cycloalkylalkyl, heterocyclyl, heterocyclylalkyl,heteroaryl, heteroarylalkyl group or the like. An acyl group can include0 to about 12, 0 to about 20, or 0 to about 40 additional carbon atomsbonded to the carbonyl group. An acyl group can include double or triplebonds within the meaning herein. An acryloyl group is an example of anacyl group. An acyl group can also include heteroatoms within themeaning herein. A nicotinoyl group (pyridyl-3-carbonyl) is an example ofan acyl group within the meaning herein. Other examples include acetyl,benzoyl, phenylacetyl, pyridylacetyl, cinnamoyl, and acryloyl groups andthe like. When the group containing the carbon atom that is bonded tothe carbonyl carbon atom contains a halogen, the group is termed a“haloacyl” group. An example is a trifluoroacetyl group.

The term “aryl” as used herein refers to cyclic aromatic hydrocarbongroups that do not contain heteroatoms in the ring. Thus aryl groupsinclude, but are not limited to, phenyl, azulenyl, heptalenyl, biphenyl,indacenyl, fluorenyl, phenanthrenyl, triphenylenyl, pyrenyl,naphthacenyl, chrysenyl, biphenylenyl, anthracenyl, and naphthyl groups.In some embodiments, aryl groups contain about 6 to about 14 carbons inthe ring portions of the groups. Aryl groups can be unsubstituted orsubstituted, as defined herein. Representative substituted aryl groupscan be mono-substituted or substituted more than once, such as, but notlimited to, a phenyl group substituted at any one or more of 2-, 3-, 4-,5-, or 6-positions of the phenyl ring, or a naphthyl group substitutedat any one or more of 2- to 8-positions thereof.

The term “heterocyclyl” as used herein refers to aromatic andnon-aromatic ring compounds containing three or more ring members, ofwhich one or more is a heteroatom such as, but not limited to, N, O, andS.

The term “alkoxy” as used herein refers to an oxygen atom connected toan alkyl group, including a cycloalkyl group, as are defined herein.Examples of linear alkoxy groups include but are not limited to methoxy,ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, and the like. Examples ofbranched alkoxy include but are not limited to isopropoxy, sec-butoxy,tert-butoxy, isopentyloxy, isohexyloxy, and the like. Examples of cyclicalkoxy include but are not limited to cyclopropyloxy, cyclobutyloxy,cyclopentyloxy, cyclohexyloxy, and the like. An alkoxy group can includeabout 1 to about 12, about 1 to about 20, or about 1 to about 40 carbonatoms bonded to the oxygen atom, and can further include double ortriple bonds, and can also include heteroatoms. For example, an allyloxygroup or a methoxyethoxy group is also an alkoxy group within themeaning herein, as is a methylenedioxy group in a context where twoadjacent atoms of a structure are substituted therewith.

The term “amine” as used herein refers to primary, secondary, andtertiary amines having, e.g., the formula N(group)₃ wherein each groupcan independently be H or non-IT, such as alkyl, aryl, and the like.Amines include but are not limited to R-NEh, for example, alkylamines,arylamines, alkylarylamines; R₂NH wherein each R is independentlyselected, such as dialkylamines, diarylamines, aralkylamines,heterocyclylamines and the like; and R₃N wherein each R is independentlyselected, such as trialkylamines, dialkylarylamines, alkyldiarylamines,triarylamines, and the like. The term “amine” also includes ammoniumions as used herein.

The term “amino group” as used herein refers to a substituent of theform —NH₂, —NHR, —NR₂, —NR₃ ⁺, wherein each R is independently selected,and protonated forms of each, except for —NR₃ ⁺, which cannot beprotonated. Accordingly, any compound substituted with an amino groupcan be viewed as an amine. An “amino group” within the meaning hereincan be a primary, secondary, tertiary, or quaternary amino group. An“alkylamino” group includes a monoalkylamino, dialkylamino, andtrialkylamino group.

The terms “halo,” “halogen,” or “halide” group, as used herein, bythemselves or as part of another substituent, mean, unless otherwisestated, a fluorine, chlorine, bromine, or iodine atom.

The term “haloalkyl” group, as used herein, includes mono-halo alkylgroups, poly-halo alkyl groups wherein all halo atoms can be the same ordifferent, and per-halo alkyl groups, wherein all hydrogen atoms arereplaced by halogen atoms, such as fluoro. Examples of haloalkyl includetrifluoromethyl, 1,1-dichloroethyl, 1,2-dichloroethyl,1,3-dibromo-3,3-difluoropropyl, perfluorobutyl, and the like.

The term “hydrocarbon” or “hydrocarbyl” as used herein refers to amolecule or functional group, respectively, that includes carbon andhydrogen atoms. The term can also refer to a molecule or functionalgroup that normally includes both carbon and hydrogen atoms but whereinall the hydrogen atoms are substituted with other functional groups. Ahydrocarbyl group can be a functional group derived from a straightchain, branched, or cyclic hydrocarbon, and can be alkyl, alkenyl,alkynyl, aryl, cycloalkyl, acyl, or any combination thereof. Hydrocarbylgroups can be shown as (C_(a)-C_(b))hydrocarbyl, wherein a and b arepositive integers and mean having any of a to b number of carbon atoms.For example, (C₁-C₄)hydrocarbyl means the hydrocarbyl group can bemethyl (C₁), ethyl (C₂), propyl (C₃), or butyl (C₄), and(C₀-C_(b))hydrocarbyl means in certain embodiments there is nohydrocarbyl group.

The term “solvent” as used herein refers to a liquid that can dissolve asolid, liquid, or gas. Non-limiting examples of solvents are silicones,organic compounds, water, alcohols, ionic liquids, and supercriticalfluids.

The term “room temperature” as used herein refers to a temperature ofabout 15° C. to 28° C.

The term “standard temperature and pressure” as used herein refers to20° C. and 101 kPa.

As used herein, “degree of polymerization” is the number of repeatingunits in a polymer.

As used herein, the term “polymer” refers to a molecule having at leastone repeating unit and can include copolymers.

The term “copolymer” as used herein refers to a polymer that includes atleast two different repeating units. A copolymer can include anysuitable number of repeating units.

The term “downhole” as used herein refers to under the surface of theearth, such as a location within or fluidly connected to a wellbore.

As used herein, the term “drilling fluid” refers to fluids, slurries, ormuds used in drilling operations downhole, such as during the formationof the wellbore.

As used herein, the term “stimulation fluid” refers to fluids orslurries used downhole during stimulation activities of the well thatcan increase the production of a well, including perforation activities.In some examples, a stimulation fluid can include a fracturing fluid oran acidizing fluid.

As used herein, the term “clean-up fluid” refers to fluids or slurriesused downhole during clean-up activities of the well, such as anytreatment to remove material obstructing the flow of desired materialfrom the subterranean formation. In one example, a clean-up fluid can bean acidification treatment to remove material formed by one or moreperforation treatments. In another example, a clean-up fluid can be usedto remove a filter cake.

As used herein, the term “fracturing fluid” refers to fluids or slurriesused downhole during fracturing operations.

As used herein, the term “spotting fluid” refers to fluids or slurriesused downhole during spotting operations, and can be any fluid designedfor localized treatment of a downhole region. In one example, a spottingfluid can include a lost circulation material for treatment of aspecific section of the wellbore, such as to seal off fractures in thewellbore and prevent sag. In another example, a spotting fluid caninclude a water control material, disproportionate permeabilitymodifier, or a relative permeability modifier. In some examples, aspotting fluid can be designed to free a stuck piece of drilling orextraction equipment, can reduce torque and drag with drillinglubricants, prevent differential sticking, promote wellbore stability,and can help to control mud weight.

As used herein, the term “completion fluid” refers to fluids or slurriesused downhole during the completion phase of a well, including cementingcompositions.

As used herein, the term “remedial treatment fluid” refers to fluids orslurries used downhole for remedial treatment of a well, and can also becalled a “work-over fluid.” Remedial treatments, also called work-overtreatments, can include treatments designed to increase or maintain theproduction rate of a well, such as stimulation or clean-up treatments.

As used herein, the term “abandonment fluid” refers to fluids orslurries used downhole during or preceding the abandonment phase of awell.

As used herein, the term “acidizing fluid” refers to fluids or slurriesused downhole during acidizing treatments. In one example, an acidizingfluid is used in a clean-up operation to remove material obstructing theflow of desired material, such as material formed during a perforationoperation. In some examples, an acidizing fluid can be used for damageremoval.

As used herein, the term “cementing fluid” refers to fluids or slurriesused during cementing operations of a well. For example, a cementingfluid can include an aqueous mixture including at least one of cementand cement kiln dust. In another example, a cementing fluid can includea curable resinous material such as a polymer that is in an at leastpartially uncured state.

As used herein, the term “water control material,” “disproportionatepermeability modifier,” or “relative permeability modifier,” refers to asolid or liquid material that interacts with aqueous material downhole,such that hydrophobic material can more easily travel to the surface andsuch that hydrophilic material (including water) can less easily travelto the surface. A water control material can be used to treat a well tocause the proportion of water produced to decrease and to cause theproportion of hydrocarbons produced to increase, such as by selectivelybinding together material between water-producing subterraneanformations and the wellbore while still allowing hydrocarbon-producingformations to maintain output.

As used herein, the term “packer fluid” refers to fluids or slurriesthat can be placed in the annular region of a well between tubing andouter casing above a packer. In various examples, the packer fluid canprovide hydrostatic pressure in order to lower differential pressureacross the sealing element, lower differential pressure on the wellboreand casing to prevent collapse, and protect metals and elastomers fromcorrosion.

As used herein, the term “fluid” refers to liquids and gels, unlessotherwise indicated.

As used herein, the term “subterranean material” or “subterraneanformation” refers to any material under the surface of the earth,including under the surface of the bottom of the ocean. For example, asubterranean formation or material can be any section of a wellbore andany section of a subterranean petroleum- or water-producing formation orregion in fluid contact with the wellbore. Placing a material in asubterranean formation can include contacting the material with anysection of a wellbore or with any subterranean region in fluid contacttherewith. Subterranean materials can include any materials placed intothe wellbore such as cement, drill shafts, liners, tubing, casing, orscreens; placing a material in a subterranean formation can includecontacting with such subterranean materials. In some examples, asubterranean formation or material can be any below-ground region thatcan produce liquid or gaseous petroleum materials, water, or any sectionbelow-ground in fluid contact therewith. For example, a subterraneanformation or material can be at least one of an area desired to befractured, a fracture or an area surrounding a fracture, and a flowpathway or an area surrounding a flow pathway, wherein a fracture or aflow pathway can be optionally fluidly connected to a subterraneanpetroleum- or water-producing region, directly or through one or morefractures or flow pathways.

As used herein, “treatment of a subterranean formation” can include anyactivity directed to extraction of water or petroleum materials from asubterranean petroleum- or water-producing formation or region, forexample, including drilling, stimulation, hydraulic fracturing,clean-up, acidizing, completion, cementing, remedial treatment,abandonment, and the like.

As used herein, a “flow pathway” downhole can include any suitablesubterranean flow pathway through which two subterranean locations arein fluid connection.

The flow pathway can be sufficient for petroleum or water to flow fromone subterranean location to the wellbore or vice-versa. A flow pathwaycan include at least one of a hydraulic fracture, and a fluid connectionacross a screen, across gravel pack, across proppant, including acrossresin-bonded proppant or proppant deposited in a fracture, and acrosssand. A flow pathway can include a natural subterranean passagewaythrough which fluids can flow. In some embodiments, a flow pathway canbe a water source and can include water. In some embodiments, a flowpathway can be a petroleum source and can include petroleum. In someembodiments, a flow pathway can be sufficient to divert from a wellbore,fracture, or flow pathway connected thereto at least one of water, adownhole fluid, or a produced hydrocarbon.

In various embodiments, salts having a positively charged counterion caninclude any suitable positively charged counterion. For example, thecounterion can be ammonium (NH₄ ⁺), or an alkali metal such as sodium(Na⁺), potassium (K⁺), or lithium (Li⁺). In some embodiments, thecounterion can have a positive charge greater than +1, which can in someembodiments complex to multiple ionized groups, such as Zn²⁺, Al³⁺, oralkaline earth metals such as Ca²⁺ or Mg²⁺.

In various embodiments, salts having a negatively charged counterion caninclude any suitable negatively charged counterion. For example, thecounterion can be a halide, such as fluoride, chloride, iodide, orbromide. In other examples, the counterion can be nitrate, hydrogensulfate, dihydrogen phosphate, bicarbonate, nitrite, perchlorate,iodate, chlorate, bromate, chlorite, hypochlorite, hypobromite, cyanide,amide, cyanate, hydroxide, permanganate. The counterion can be aconjugate base of any carboxylic acid, such as acetate or formate. Insome embodiments, a counterion can have a negative charge greater than−1, which can in some embodiments complex to multiple ionized groups,such as oxide, sulfide, nitride, arsenate, phosphate, arsenite, hydrogenphosphate, sulfate, thiosulfate, sulfite, carbonate, chromate,dichromate, peroxide, or oxalate.

In various embodiments, the present invention provides a method oftreating a subterranean formation. The method includes placing in thesubterranean formation a demulsifier composition. The demulsifiercomposition includes an alkanolamide surfactant that is a(C₁-C₅₀)hydrocarbyl amide having groups R¹ and R² substituted on theamide nitrogen, wherein R¹ and R² are each independently selected fromthe group consisting of —H, —(C₁-C₅₀)hydrocarbyl, and—(C₁-C₅₀)hydrocarbylene-OH, wherein at least one of R¹ and R² is—(C₁-C₅₀)hydrocarbylene-OH. The demulsifier composition includes analkoxylated alcohol surfactant that is a (C₁-C₅₀)hydrocarbyl-OH having a—((C₂-C₃)alkylene-O)_(n)—H group on the —OH group, wherein n is about 1to about 100. The demulsifier composition also includes an amine-oxidesurfactant. At each occurrence the (C₁-C₅₀)hydrocarbyl and(C₁-C₅₀)hydrocarbylene are substituted or unsubstituted and areindependently selected.

In various embodiments, the present invention provides a method oftreating a subterranean formation. The method includes placing in thesubterranean formation a demulsifier composition. The demulsifiercomposition includes an aqueous phase. The demulsifier compositionincludes an oil phase, wherein the demulsifier composition includes anemulsion including the aqueous phase and the oil phase. The demulsifiercomposition includes an alkanolamide surfactant that has the structure:

The variable R³ is a substituted or unsubstituted (C₁₂-C₂₅)hydrocarbylof a tall oil fatty acid having the structure R³—C(O)—OH. The variablesR¹ and R² are each independently —(C₁-C₁₀)alkylene-OH. The demulsifiercomposition includes an alkoxylated alcohol surfactant that is a(C₁₀-C₂₀)hydrocarbon including a secondary alcohol group, wherein the(C₁₀-C₂₀)hydrocarbon is otherwise unsubstituted, wherein the secondaryalcohol group includes a —(CH₂—CH₂—O)₅₋₁₀—H group thereon. Thedemulsifier composition includes an amine-oxide surfactant having thestructure:

The variable R⁶ is (C₁₁-C₁₃)alkyl. The variable R⁷ is (C₁-C₅)alkylene.At each occurrence, R⁸ is independently (C₁-C₅)alkyl.

In various embodiments, the present invention provides a method oftreating a subterranean formation. The method includes placing in thesubterranean formation a demulsifier composition. The demulsifiercomposition includes an aqueous phase that is about 10 wt % to about 80wt % of the demulsifier composition. The demulsifier compositionincludes an oil phase that is about 10 wt % to about 80 wt % of thedemulsifier composition, wherein the demulsifier composition includes anemulsion including the aqueous phase and the oil phase. The demulsifiercomposition includes a (C₁-C₅)alkyl alcohol that is about 5 wt % toabout 30 wt % of the demulsifier composition. The demulsifiercomposition includes an alkanolamide surfactant that is about 5 wt % toabout 40 wt % of the demulsifier composition, wherein the alkanolamidesurfactant has the structure:

The variable R³ is a substituted or unsubstituted (C₁₅-C₁₇)hydrocarbylof a tall oil fatty acid having the structure R³—C(O)—OH. The variablesR¹ and R² are each —CH₂—CH₂—OH. The demulsifier composition includes analkoxylated alcohol surfactant that is about 5 wt % to about 40 wt % ofthe demulsifier composition, wherein the alkoxylated alcohol surfactantis a (C₁₅)hydrocarbon including a secondary alcohol group, wherein the(C₁₅)hydrocarbon is otherwise unsubstituted, wherein the secondaryalcohol group includes a —(CH₂—CH₂—O)₇—H group thereon. The demulsifiercomposition includes an amine-oxide surfactant that is about 0.01 wt %to about 20 wt % of the demulsifier composition, wherein the amine-oxidesurfactant has the structure:

The demulsifier composition includes an amine-oxide surfactant that isabout 0.01 wt % to about 20 wt % of the demulsifier composition, whereinthe amine-oxide surfactant has the structure:

In vanous embodiments, the present invention provides a method oftreating a produced petroleum including an emulsion. The method includescontacting the produced petroleum including the emulsion with ademulsifier composition to reduce or eliminate the emulsion. Thedemulsifier composition includes an alkanolamide surfactant that is a(C₁-C₅₀)hydrocarbyl amide having groups R¹ and R² substituted on theamide nitrogen, wherein R¹ and R² are each independently selected fromthe group consisting of —H, —(C₁-C₅₀)hydrocarbyl, and—(C₁-C₅₀)hydrocarbylene-OH, wherein at least one of R¹ and R² is—(C₁-C₅₀)hydrocarbylene-OH. The demulsifier composition includes analkoxylated alcohol surfactant that is a (C₁-C₅₀)hydrocarbyl-OH having a—((C₂-C₃)alkylene-O)_(n)—H group on the —OH group, wherein n is about 1to about 100. The demulsifier composition includes an amine-oxidesurfactant. At each occurrence the (C₁-C₅₀)hydrocarbyl and(C₁-C₅₀)hydrocarbylene are substituted or unsubstituted and areindependently selected.

In various embodiments, the present invention provides a systemincluding a tubular disposed in a subterranean formation. The systemalso includes a pump configured to pump a demulsifier composition in thesubterranean formation through the tubular. The demulsifier compositionincludes an alkanolamide surfactant that is a (C₁-C₅₀)hydrocarbyl amidehaving groups R¹ and R² substituted on the amide nitrogen, wherein R¹and R² are each independently selected from the group consisting of —H,—(C₁-C₅₀)hydrocarbyl, and —(C₁-C₅₀)hydrocarbylene-OH, wherein at leastone of R¹ and R² is —(C₁-C₅₀)hydrocarbylene-OH. The demulsifiercomposition includes an alkoxylated alcohol surfactant that is a(C₁-C₅₀)hydrocarbyl-OH having a —((C₂-C₃)alkylene-O)_(n)—H group on the—OH group, wherein n is about 1 to about 100. The demulsifiercomposition also includes an amine-oxide surfactant. At each occurrencethe (C₁-C₅₀)hydrocarbyl and (C₁-C₅₀)hydrocarbylene are substituted orunsubstituted and are independently selected.

In various embodiments, the present invention provides a demulsifiercomposition. The demulsifier composition includes an alkanolamidesurfactant that is a (C₁-C₅₀)hydrocarbyl amide having groups R¹ and R²substituted on the amide nitrogen, wherein R¹ and R² are eachindependently selected from the group consisting of —H,—(C₁-C₅₀)hydrocarbyl, and —(C₁-C₅₀)hydrocarbylene-OH, wherein at leastone of R¹ and R² is —(C₁-C₅₀)hydrocarbylene-OH. The demulsifiercomposition includes an alkoxylated alcohol surfactant that is a(C₁-C₅₀)hydrocarbyl-OH having a —((C₂-C₃)alkylene-O)_(n)—H group on the—OH group, wherein n is about 1 to about 100. The demulsifiercomposition also includes an amine-oxide surfactant. At each occurrencethe (C₁-C₅₀)hydrocarbyl and (C₁-C₅₀)hydrocarbylene are substituted orunsubstituted and are independently selected.

In various embodiments, the present invention provides a demulsifiercomposition. The demulsifier composition includes an aqueous phase. Thedemulsifier composition includes an oil phase, wherein the demulsifiercomposition includes an emulsion including the aqueous phase and the oilphase. The demulsifier composition includes an alkanolamide surfactantthat has the structure:

The variable R³ is a substituted or unsubstituted (C₁₂-C₂₅)hydrocarbylof a tall oil fatty acid having the structure R³—C(O)—OH. The variablesR¹ and R² are each independently —(C₁-C₁₀)alkylene-OH. The demulsifiercomposition includes an alkoxylated alcohol surfactant that is a(C₁₀-C₂₀)hydrocarbon including a secondary alcohol group, wherein the(C₁₀-C₂₀)hydrocarbon is otherwise unsubstituted, wherein the secondaryalcohol group includes a —(CH₂—CH₂—O)₅₋₁₀—H group thereon. Thedemulsifier composition includes an amine-oxide surfactant having thestructure:

The variable R⁶ is (C₁₁-C₁₃)alkyl. The variable R⁷ is (C₁-C₅)alkylene.At each occurrence, R⁸ is independently (C₁-C₅)alkyl.

In various embodiments, the present invention provides a demulsifiercomposition. The demulsifier composition includes an aqueous phase thatis about 10 wt % to about 80 wt % of the demulsifier composition. Thedemulsifier composition includes an oil phase that is about 10 wt % toabout 80 wt % of the demulsifier composition, wherein the demulsifiercomposition includes an emulsion including the aqueous phase and the oilphase. The demulsifier composition includes a (C₁-C₅)alkyl alcohol thatis about 5 wt % to about 30 wt % of the demulsifier composition. Thedemulsifier composition includes an alkanolamide surfactant that isabout 5 wt % to about 40 wt % of the demulsifier composition, whereinthe alkanolamide surfactant has the structure:

The variable R³ is a substituted or unsubstituted (C₁₅-C₁₇)hydrocarbylof a tall oil fatty acid having the structure R³—C(O)—OH. The variablesR¹ and R² are each —CH₂—CH₂—OH. The demulsifier composition includes analkoxylated alcohol surfactant that is about 5 wt % to about 40 wt % ofthe demulsifier composition, wherein the alkoxylated alcohol surfactantis a (C₁₅)hydrocarbon including a secondary alcohol group, wherein the(C₁₅)hydrocarbon is otherwise unsubstituted, wherein the secondaryalcohol group includes a —(CH₂—CH₂—O)₇—H group thereon. The demulsifiercomposition includes an amine-oxide surfactant that is about 0.01 wt %to about 20 wt % of the demulsifier composition, wherein the amine-oxidesurfactant has the structure:

The demulsifier composition includes an amine-oxide surfactant that isabout 0.01 wt % to about 20 wt % of the demulsifier composition, whereinthe amine-oxide surfactant has the structure:

In various embodiments, the present invention provides a method ofpreparing a demulsifier composition for treatment of a subterraneanformation or of produced petroleum including an emulsion. The methodincludes forming a demulsifier composition. The demulsifier compositionincludes an alkanolamide surfactant that is a (C₁-C₅₀)hydrocarbyl amidehaving groups R¹ and R² substituted on the amide nitrogen, wherein R¹and R² are each independently selected from the group consisting of —H,—(C₁-C₅₀)hydrocarbyl, and —(C₁-C₅₀)hydrocarbylene-OH, wherein at leastone of R¹ and R² is —(C₁-C₅₀)hydrocarbylene-OH. The demulsifiercomposition includes an alkoxylated alcohol surfactant that is a(C₁-C₅₀)hydrocarbyl-OH having a —((C₂-C₃)alkylene-O)_(n)—H group on the—OH group, wherein n is about 1 to about 100. The demulsifiercomposition also includes an amine-oxide surfactant. At each occurrencethe (C₁-C₅₀)hydrocarbyl and (C₁-C₅₀)hydrocarbylene are substituted orunsubstituted and are independently selected.

In various embodiments, the demulsifier composition has certainadvantages over other demulsifier compositions, at least some of whichare unexpected. For example, in various embodiments, the demulsifiercomposition can break an emulsion more rapidly, at lower temperatures,or a combination thereof, as compared to other demulsifier compositions.

In various embodiments, the demulsifier composition can decrease oreliminate emulsions in various subterranean treatment fluids, such asstimulation fluids (e.g., fracturing fluids), thereby providing betterdemulsification and better permeability of subterranean treatment fluidsthan other demulsifier compositions. In various embodiments, thedemulsifier composition can decrease or eliminate emulsion-inducedviscosification of various subterranean treatment fluids, such asstimulation fluids (e.g., fracturing fluids), thereby providing bettercontrol over emulsion-induced viscosification and better permeability oftreatment fluids than other demulsifier compositions. In variousembodiments, the demulsifier composition can reduce or eliminateemulsions in fluids produced after performing various subterraneanoperations, such as after performing stimulation operations, therebyproviding better demulsification and better permeability of producedfluids than other demulsifier compositions. In various embodiments, thedemulsifier composition can decrease or minimize the emulsion-inducedviscosification of fluids produced after various subterraneanoperations, such as after performing stimulation operations, therebyproviding better control over emulsion-induced viscosification andbetter permeability of produced fluids than other demulsifiercompositions. In various embodiments, the demulsifier composition candecrease or eliminate emulsions when used to treat a produced fluidafter it has been produced, thereby providing better post-productiondemulsification of produced fluids than other demulsifier compositions.In various embodiments, the demulsifier composition can decreasecapillary pressure in the subterranean formation, alter wettability ofthe subterranean formation, or a combination thereof, thereby enhancingflowback of produced materials.

In various embodiments, the demulsifier composition can be used in anemulsion form or in a non-emulsion form (e.g., with no oil phase, orincluding an oil phase but free of emulsions), thereby providing moreversatility than other demulsifier compositions. In various embodiments,the demulsifier composition in anon-emulsion form without an oil phasecan facilitate adsorption of the demulsifier composition into thesubterranean formation. The enhanced adsorption of the demulsifiercomposition can increase the wettability of the subterranean formation,which can lower the cap pressure, helping the demulsifier compositionpropagate through the subterranean formation.

In various embodiments, the demulsifier composition can be used in anemulsion form, wherein the demulsifier composition can surprisinglybreak other emulsions. In various embodiments, the demulsifiercomposition can include an emulsion having a lower interfacial tensionthan other emulsions useful as demulsifier compositions. In variousembodiments, an emulsion in the demulsifier composition can be morestable under high salinity, can be more stable at higher temperatures,can have a lower freezing point, or a combination thereof, as comparedto emulsions in other demulsifier compositions. In various embodiments,the demulsifier composition can have a higher RockPerm℠ Gas value (RPG),a higher RockPerm℠ Value (RPV), or a combination thereon, as compared toother demulsifier compositions.

In various embodiments, the demulsifier composition can be free of orcan have less ethoxylated alkylphenols (e.g., alkyl-substituted phenolshaving a monoethoxy or poly ethoxy group on the hydroxy group of thephenol) or less ethyoxylated nonylphenols (e.g., nonyl-substitutedphenols having a monoethoxy or poly ethoxy group on the hydroxy group ofthe phenol) than other demulsifier compositions. In various embodiments,the demulsifier composition can be more environmentally-friendly, morebiodegradable, or a combination thereof, as compared to otherdemulsifier compositions.

Method of Treating a Subterranean Formation.

In various embodiments, the present invention provides a method oftreating a subterranean formation. The method can include placing in thesubterranean formation a demulsifier composition, such as any embodimentof a demulsifier composition described herein. The demulsifiercomposition can include an alkanolamide surfactant that is a(C₁-C₅₀)hydrocarbyl amide having groups R¹ and R² substituted on theamide nitrogen, wherein R¹ and R² are each independently selected fromthe group consisting of —H, —(C₁-C₅₀)hydrocarbyl, and—(C₁-C₅₀)hydrocarbylene-OH, wherein at least one of R¹ and R² is—(C₁-C₅₀)hydrocarbylene-OH. The demulsifier composition can include analkoxylated alcohol surfactant that is a (C₁-C₅₀)hydrocarbyl-OH having a—((C₂-C₃)alkylene-O)_(n)—H group on the —OH group, wherein n is about 1to about 100. The demulsifier composition can also include anamine-oxide surfactant. At each occurrence the (C₁-C₅₀)hydrocarbyl and(C₁-C₅₀)hydrocarbylene can be substituted or unsubstituted and can beindependently selected.

In some embodiments, the method includes obtaining or providing thedemulsifier composition. The obtaining or providing of the demulsifiercomposition can occur at any suitable time and at any suitable location.The obtaining or providing of the demulsifier composition can occurabove the surface (e.g., one or more components of the demulsifiercomposition can be combined above-surface to form the demulsifiercomposition). The obtaining or providing of the demulsifier compositioncan occur in the subterranean formation (e.g., one or more components ofthe demulsifier composition can be combined downhole to form thedemulsifier composition).

The placing of the demulsifier composition in the subterranean formationcan include contacting the demulsifier composition and any suitable partof the subterranean formation, or contacting the demulsifier compositionand a subterranean material, such as any suitable subterranean material.The subterranean formation can be any suitable subterranean formation.In some examples, the placing of the demulsifier composition in thesubterranean formation includes contacting the demulsifier compositionwith or placing the demulsifier composition in at least one of afracture, at least a part of an area surrounding a fracture, a flowpathway, an area surrounding a flow pathway, and an area desired to befractured. The placing of the demulsifier composition in thesubterranean formation can be any suitable placing and can include anysuitable contacting between the subterranean formation and thedemulsifier composition. The placing of the demulsifier composition inthe subterranean formation can include at least partially depositing thedemulsifier composition in a fracture, flow pathway, or area surroundingthe same.

In some embodiments, the demulsifier composition can be placed in thesubterranean formation neat. In some embodiments, the demulsifiercomposition can be placed in the subterranean formation as a componentof another composition. For example, a subterranean treatment fluid caninclude the demulsifier composition, wherein the subterranean treatmentfluid is a stimulation fluid, a hydraulic fracturing fluid, a drillingfluid, a spotting fluid, a clean-up fluid, a completion fluid, aremedial treatment fluid, an abandonment fluid, a pill, an acidizingfluid, a cementing fluid, a packer fluid, a logging fluid, or acombination thereof. The placing of the demulsifier composition in thesubterranean formation can including placing the subterranean treatmentfluid that includes the demulsifier composition in the subterraneanformation. The method can include performing a subterranean formationtreatment operation in the subterranean formation, such as using thesubterranean treatment fluid that includes the demulsifier composition,or using a subterranean treatment fluid that is free of the demulsifiercomposition but with placement of the demulsifier composition in thesubterranean formation before or after placing the subterraneantreatment fluid in the subterranean formation. The method can includehydraulic fracturing, stimulation, drilling, spotting, clean-up,completion, remedial treatment, abandonment, acidizing, cementing,packing, logging, or a combination thereof. The subterranean treatmentfluid can be a hydraulic fracturing fluid. The method can includehydraulically fracturing the subterranean formation with the demulsifiercomposition (e.g., which can be injected adjacent to a hydraulicfracturing fluid) or with a hydraulic fracturing fluid including thedemulsifier composition.

The method can include hydraulic fracturing, such as a method ofhydraulic fracturing to generate a fracture or flow pathway. The placingof the demulsifier composition in the subterranean formation or thecontacting of the subterranean formation and the hydraulic fracturingcan occur at any time with respect to one another; for example, thehydraulic fracturing can occur at least one of before, during, and afterthe contacting or placing. In some embodiments, the contacting orplacing occurs during the hydraulic fracturing, such as during anysuitable stage of the hydraulic fracturing, such as during at least oneof a pre-pad stage (e.g., during injection of water with no proppant,and additionally optionally mid- to low-strength acid), a pad stage(e.g., during injection of fluid only with no proppant, with someviscosifier, such as to begin to break into an area and initiatefractures to produce sufficient penetration and width to allowproppant-laden later stages to enter), or a slurry stage of thefracturing (e.g., viscous fluid with proppant). The method can includeperforming a stimulation treatment at least one of before, during, andafter placing the demulsifier composition in the subterranean formationin the fracture, flow pathway, or area surrounding the same. Thestimulation treatment can be, for example, at least one of perforating,acidizing, injecting of cleaning fluids, propellant stimulation, andhydraulic fracturing. In some embodiments, the stimulation treatment atleast partially generates a fracture or flow pathway where thedemulsifier composition is placed in or contacted to, or the demulsifiercomposition is placed in or contacted to an area surrounding thegenerated fracture or flow pathway.

In various embodiments, the method includes reducing or eliminating anemulsion in the subterranean formation with one or more components ofthe demulsifier composition. In various embodiments, the method includesreducing or eliminating the formation of an emulsion in the subterraneanformation with one or more components of the demulsifier composition. Inother embodiments, an emulsion can be reduced or eliminated by one ormore components of the demulsifier composition, or the formation of anemulsion can be reduced or eliminated by one or more components of thedemulsifier composition, after the method is carried out.

In some embodiments, the demulsifier composition include water, e.g., awater phase. The water can be any suitable proportion of the demulsifiercomposition, such as about 0.01 wt % to about 99.99 wt % of thedemulsifier composition, about 10 wt % to about 80 wt %, or about 0 wt%, or about 0.01 wt % or less, or less than, equal to, or greater thanabout 0.1 wt %, 1, 2, 3, 4, 5, 6, 8, 10, 12, 14, 16, 18, 20, 25, 30, 35,40, 45, 50, 55, 60, 65, 70, 75, 80, 82, 84, 86, 88, 90, 91, 92, 93, 94,95, 96, 97, 98, 99, 99.9 wt %, or about 99.99 wt % or more of thedemulsifier composition. The water can be any suitable water, such asfresh water, brine, produced water, flowback water, brackish water, orsea water.

The water can be a salt water. The salt can be any suitable salt, suchas at least one of NaBr, CaCh, CaBr₂, ZnBr₂, KCl, NaCl, a carbonatesalt, a sulfonate salt, sulfite salts, sulfide salts, a phosphate salt,a phosphonate salt, a magnesium salt, a bromide salt, a formate salt, anacetate salt, and a nitrate salt. The water can have any suitable totaldissolved solids level, such as about 1,000 mg/L to about 250,000 mg/L,or about 1,000 mg/L or less, or about 5,000 mg/L, 10,000, 15,000,20,000, 25,000, 30,000, 40,000, 50,000, 75,000, 100,000, 125.000,150,000, 175,000, 200,000, 225,000, or about 250,000 mg/L or more. Theaqueous liquid can have any suitable salt concentration, such as about1,000 ppm to about 300,000 ppm, or about 1,000 ppm to about 150,000 ppm,or about 1,000 ppm or less, or about 5,000 ppm, 10.000, 15,000, 20,000,25,000, 30,000, 40,000, 50,000, 75,000, 100,000, 125,000, 150,000,175.000, 200,000, 225,000, 250,000, 275,000, or about 300,000 ppm ormore. In some examples, the water can have a concentration of at leastone of NaBr, CaCl₂, CaBr₂, ZnBr₂, KCl, and NaCl of about 0.1% w/v toabout 20% w/v, or about 0.1% w/v or less, or about 0.5% w/v, 1, 2, 3, 4,5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23,24, 25, 26, 27, 28, 29, or about 30% w/v or more. In variousembodiments, an emulsion in the demulsifier composition can be stableunder conditions of high salinity in the aqueous phase of the emulsion,such as any level of salinity described herein.

The demulsifier composition can include an organic solvent. Thedemulsifier composition can include one organic solvent or more than oneorganic solvent. The one or more organic solvents can be any suitableproportion of the demulsifier composition, such as about 0.01 wt % toabout 99.99 wt % of the demulsifier composition, about 5 wt % to about30 wt %, about 0 wt %, or about 0.01 wt % or less, or less than, equalto, or greater than about 0.1 wt %, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12,14, 16, 18, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 82, 84,86, 88, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 99.9 wt %, or about99.99 wt % or more of the demulsifier composition. The organic solventcan be a water-miscible organic solvent. The organic solvent can be asubstituted or unsubstituted (C₁-C₂₀)hydrocarbyl alcohol. The organicsolvent can be a (C₁-C₅)alkyl alcohol. The organic solvent can beethanol, iso-propanol, n-propanol, n-butanol, s-butanol, t-butanol,n-pentanol, a pentanol isomer, or a combination thereof. The organicsolvent can be iso-propanol. In some embodiments, the organic solventcan lower the freeze point or pour point of the demulsifier composition.

The demulsifier composition can include an oil, e.g., an oil phase. Theoil can include one or more oil components. The oil can form anysuitable proportion of the demulsifier composition, such as about 0.01wt % to about 99.99 wt %, about 10 wt % to about 80 wt %, about 0 wt %,or about 0.01 wt % or less, or less than, equal to, or greater thanabout 0.1 wt %, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, 22,24, 26, 28, 30, 32, 34, 36, 38, 40, 45, 50, 55, 60, 65, 70, 75, 80, 82,84, 86, 88, 90, 91, 92, 93, 94, 95, 96, 97, 99, 99.9 wt %, or about99.99 wt % or more of the demulsifier composition. The oil phase can beor can include a (C₅-C₅)hydrocarbon, a terpene, D-linonene, a dipentene,a pinene, an isoprene adduct, an isomer of an isoprene adduct (e.g., aC₅-C₁₅ isomer, such as a C₁₀ isomer), a (C₅-C₅₀)alkane, a(C₅-C₅₀)isoalkane, a (C₅-C₅₀)alkene, a silicone oil, a (C₁-C₅)alkylester of a substituted or unsubstituted (C₁-C₂₀)carboxylic acid, ethyllactate, or a combination thereof. The oil phase can include or can bepetroleum distillates, having any suitable boiling point range, such aslight petroleum distillates (e.g., having a boiling point range betweenabout 100° C. and about 300° C. or greater than about 200° C. and lessthan about 250° C.). The oil phase can be hydrotreated petroleumdistillate (e.g, dearomatized petroleum distillates). The oil phase canbe hydrotreated light petroleum distillates having a boiling point rangegreater than about 200° C. and less than about 250° C.

In some embodiments, the demulsifier composition includes both theaqueous phase and the oil phase. The aqueous phase and the oil phase canbe separate in the demulsifier composition (e.g., not mixed). Theaqueous phase and the oil phase can be combined in the demulsifiercomposition as an emulsion of the aqueous phase and the oil phase. Theemulsion can be any suitable emulsion. In some embodiments, the aqueousphase is the outer phase and the oil phase is the inner phase. In someembodiments, the oil phase is the outer phase and the aqueous phase isthe inner phase. The size (e.g., the largest dimension) of the dropletsof the inner phase of the emulsion in the outer phase of the emulsioncan be any suitable size, such as about 0.001 micron to about 5 mm, orabout 1 micron to about 1,000 microns, or about 0.005 microns to about100 microns, or about 0.005 microns to about 0.3 microns, or about 0.01microns to about 0.15 microns, or about 0.001 microns or less, or lessthan, equal to, or greater than about 0.005 microns, 0.01, 0.02, 0.03,0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15,0.16, 0.17, 0.18, 0.19, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.6, 0.7,0.8, 0.9, 1, 2, 3, 4, 5, 6, 8, 10, 15, 20, 25, 50, 75, 100, 125, 150,175, 200, 250, 300, 350, 400, 450, 500, 600, 700, 800, 900 microns, 1mm, 2, 3, 4 mm, or about 5 mm or more. The emulsion can be amicroemulsion, with a size of the droplets of the inner phase of theemulsion in the outer phase of the emulsion being about 0.001 microns toabout 1,000 microns, about 1 micron to about 1,000 microns, or about 1micron to about 100 microns.

The emulsion can become unstable upon dilution with water, such that theemulsion begins to break, at least partially breaks, or substantiallyfully breaks. In some embodiments, the emulsion can be unstable whendiluted to a concentration of about 0.2 wt % in water. In someembodiments, the emulsion can be unstable at a concentration of about0.2 wt % in brine. In some embodiments, the emulsion can be unstable ata concentration of 0.2 wt % in water including 7 wt % KCl.

The present method is not limited to any specific mechanism of action.The emulsion can include at least one surfactant that is more readilysoluble in oil, e.g., an alkanolamide surfactant. Upon dilution, thealkanolamide surfactant can partition into a large native (e.g.,formation) oil phase, facilitating demulsification of the formation oilphase. The demulsifying behavior is enhanced by the presence of analkoxylated alcohol surfactant and an amine-oxide surfactant.

The demulsifier composition can have any suitable RockPerm℠ Value (RPV),such as about 1 to about 100, or about 3 to about 40, or about 1 ormore, or less than, equal to, or greater than about 2, 3, 4, 5, 6, 7, 8,9, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 45,50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or about 100 or more.

The demulsifier composition can have any suitable RockPerm℠ Gas value(RPG), such as about 40 to about 100, or about 50 to about 80, or about40 or less, or less than, equal to, or more than about 42, 44, 46, 48,50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84,86, 88, 90, 95, or about 100 or more.

In various embodiments, an emulsion in the demulsifier composition canbe stable at high temperatures, such as at temperatures up to about 50°C. to about 400° C., or about 100° C. to about 300° C., or up to about50° C. or more, or up to less than, equal to, or greater than about 60°C., 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200,220, 240, 260, 280, 300, 350, or about 400° C. or more.

In various embodiments, an emulsion in the demulsifier composition canbe stable under conditions of high salinity, wherein the emulsion isplaced into an aqueous solution having high salinity. For example, theemulsion can be stable under salinity conditions including any suitabledissolved salt, such as at least one of NaBr, CaCl₂, CaBr₂, ZnBr₂, KCl,NaCl, a carbonate salt, a sulfonate salt, sulfite salts, sulfide salts,a phosphate salt, a phosphonate salt, a magnesium salt, a bromide salt,a formate salt, an acetate salt, and a nitrate salt, at any suitableconcentration. The emulsion can be stable in the presence of a totaldissolved solids level of about 0 mg/L to about 250,000 mg/L, or about1,000 mg/L or less, or about 5,000 mg/L, 10,000, 15,000, 20,000, 25,000,30,000, 40,000, 50,000, 75,000, 100,000, 125.000, 150,000, 175,000,200,000, 225,000, or about 250,000 mg/L or more. The emulsion can bestable in the presence of any suitable salt concentration, such as about1,000 ppm to about 300,000 ppm, or about 1,000 ppm to about 150,000 ppm,or about 1,000 ppm or less, or about 5,000 ppm, 10,000, 15,000, 20,000,25,000, 30,000, 40,000, 50,000, 75,000, 100,000, 125.000, 150,000,175,000, 200,000, 225,000, 250,000, 275,000, or about 300,000 ppm ormore. The emulsion can be stable in the presence of a concentration ofat least one of NaBr, CaCh, CaBr₂, ZnBr₂, KCl, and NaCl of about 0.1%w/v to about 20% w/v, or about 0.1% w/v or less, or about 0.5% w/v, 1,2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,22, 23, 24, 25, 26, 27, 28, 29, or about 30% w/v or more.

In various embodiments, the demulsifier composition can have a lowerfreezing point. For example, the demulsifier composition can freezebelow about 10° C., or below more than, equal to, or less than about 5°C., 0, −5, −10, −15, −20, −25, −30, −35, −40, −45° C., or about −50° C.or less.

Alkanolamide Surfactant.

The demulsifier composition can include an alkanolamide surfactant. Thedemulsifier composition can include one alkanolamide surfactant or morethan one alkanolamide surfactant. The one or more alkanolamidesurfactants can form any suitable proportion of the demulsifiercomposition, such as about 1 wt % to about 90 wt %, about 5 wt % toabout 40 wt %, or about 1 wt % or less, or less than, equal to, orgreater than about 2 wt %, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,16, 17, 18, 19, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 45, 50, 55,60, 65, 70, 75, 80, 85 wt %, or about 90 wt % or more of the demulsifiercomposition. In various embodiments, the alkanolamide surfactant caneffectively solubilize an oil phase of the demulsifier composition.

The alkanolamide surfactant can be a (C₁-C₅₀)hydrocarbyl amide havinggroups R¹ and R² substituted on the amide nitrogen, wherein R¹ and R²can each be independently selected from the group consisting of —H,—(C₁-C₅₀)hydrocarbyl, and —(C₁-C₅₀)hydrocarbylene-OH, wherein at leastone of R¹ and R² can be —(C₁-C₅₀)hydrocarbylene-OH, wherein the —OHgroup can be substituted at any suitable position on the—(C₁-C₅₀)hydrocarbylene group, such as a pendant secondary position or aterminal primary position. The alkanolamide surfactant can have thestructure:

The variable R³ can be the (C₁-C₅₀)hydrocarbyl group. The alkanolamidesurfactant can be an alkanolamide of a tall oil fatty acid. Thealkanolamide surfactant can be the alkanolamide of a tall oil fatty acidhaving the structure R³—C(O)—OH. The (C₁-C₅₀)hydrocarbyl groups and the—(C₁-C₅₀)hydrocarbylene-OH group of the alkanolamide surfactant can beunsubstituted. The variable R³ can be a substituted or unsubstituted(C₁₂-C₂₅)hydrocarbyl. The variable R³ can be a substituted orunsubstituted (C₁₅-C₁₇)hydrocarbyl. The alkanolamide surfactant can be atall oil (C₁₆-C₁₈)fatty acid alkanolamide. Both of R¹ and R² can beindependently —(C₁-C₅₀)hydrocarbylene-OH. One of R¹ and R² can beindependently —(C₁-C₅₀)hydrocarbylene-OH. The variables R¹ and R² can beindependently selected from —H, substituted or unsubstituted(C₁-C₁₀)hydrocarbyl, and substituted or unsubstituted—(C₁-C₁₀)hydrocarbylene-OH. The variables R¹ and R² can be independentlyselected from —H, —(C₁-C₅)alkyl, and —(C₁-C₅)alkylene-OH. The variablesR¹ and R² are can be each —CH₂—CH₂—OH.

The alkanolamide surfactant can have the structure:

The variable R³ can be a substituted or unsubstituted(C₁₂-C₂₅)hydrocarbyl or (C₁₅-C₁₇)hydrocarbyl of a tall oil fatty acidhaving the structure R³—C(O)—OH. The variables R¹ and R² can each be—(C₁-C₁₀)alkylene-OH or —CH₂—CH₂—OH.

Alkoxylated Alcohol Surfactant.

The demulsifier composition can include an alkoxylated alcoholsurfactant. The demulsifier composition can include one alkoxylatedalcohol surfactant or more than one alkoxylated alcohol surfactant. Theone or more alkoxylated alcohol surfactants can form any suitableproportion of the demulsifier composition, such as about 1 wt % to about90 wt %, about 5 wt % to about 40 wt %, or about 1 wt % or less, or lessthan, equal to, or greater than about 2 wt %, 3, 4, 5, 6, 7, 8, 9, 10,11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 22, 24, 26, 28, 30, 32, 34, 36,38, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, or about 90 wt % or more ofthe demulsifier composition. In various embodiments, the alkoxylatedalcohol surfactant can provide high temperature stability and salttolerance to an emulsion in the demulsifier composition.

The alxoylated alcohol surfactant can be a (C₁-C₅₀)hydrocarbyl-OH havinga —((C₂-C₃)alkylene-O)_(n)—H group on the —OH group. The alkoxylatedalcohol surfactant can have the structure:

R⁴—O—R⁵.

The variable R⁴ can be the (C₁-C₅₀)hydrocarbyl group. The alcohol can bea secondary alcohol. The oxygen atom can be bound to R⁴ at a carbon atomhaving two other carbon atoms bound thereto in R⁴. The variable R⁴ canbe unsubstituted aside from the alcohol. The variable R⁴ can be a(C₅-C₂₅)hydrocarbyl group. The variable R⁴ can be a (C₁₀-C₂₀)hydrocarbylgroup. The variable R⁴ can be a (C₁₅)hydrocarbyl group. The variable R⁵can be the —((C₂-C₃)alkylene-O)_(n)—H group. The variable R⁵ can be a-(ethylene-O)_(n)—H group. The variable R⁵ can be a -(ethylene-O)₇—Hgroup. The variable n can be about 1 to about 100, about 2 to about 20,about 5 to about 10, or about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,14, 15, 16, 17, 18, 19, 20, or less than, equal to, or greater thanabout 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, orabout 100 or more. The variable n can be about 7.

The alkoxylated alcohol surfactant can be a (C₁₀₋₂₀)hydrocarbonincluding a secondary alcohol group, wherein the (C₁₀₋₂₀)hydrocarbon isotherwise unsubstituted, wherein the secondary alcohol group includes a—(CH₂—CH₂—O)₅₋₁₀—H group thereon. The alkoxylated alcohol surfactant canbe a (C₁₅)hydrocarbon including a secondary alcohol group, wherein the(C₁₅)hydrocarbon is otherwise unsubstituted, wherein the secondaryalcohol group includes a —(CH₂—CH₂—O)₇—H group thereon.

Amine-Oxide Surfactant.

The demulsifier composition can include an amine-oxide surfactant. Thedemulsifier composition can include one amine-oxide surfactant or morethan one amine-oxide surfactant. The one or more amine-oxide surfactantscan form any suitable proportion of the demulsifier composition, such asabout 0.01 wt % to about 90 wt %, about 0.01 wt % to about 20 wt %, orabout 0.01 wt % or less, or less than, equal to, or greater than about0.1 wt %, 0.2, 0.4, 0.6, 0.8, 1, 1.2, 1.4, 1.6, 1.8, 2, 2.2, 2.4, 2.6,2.8, 3, 3.5, 4, 4.5, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, 22, 24, 26,28, 30, 32, 34, 36, 38, 40, 42, 44, 45, 50, 55, 60, 65, 70, 75, 80, 85wt %, or about 90 wt % or more. In various embodiments, the amine-oxidesurfactant can provide improved performance, such as improveddemulsification performance, as compared to a corresponding demulsifiercomposition that lacks the amine-oxide surfactant.

The amine-oxide surfactant can have the structure:

The variable R⁶ can be substituted or unsubstituted (C₁-C₅₀)hydrocarbyl.The variable R⁶ can be (C₅-C₃₀)hydrocarbyl. The variable R⁶ can be(C₅-C₂₀)alkyl. The variable R⁶ can be (C₁₁-C₁₃)alkyl. The variable R⁷can be substituted or unsubstituted (C₁-C₂₀)hydrocarbylene. The variableR⁷ can be a (C₁-C₁₀)hydrocarbylene. The variable R⁷ can be a(C₁-C₅)alkylene. The variable R⁷ can be propylene. At each occurrence,R⁸ can be independently substituted or unsubstituted(C₁-C₂₀)hydrocarbyl. The variable R⁸ can be (C₁-C₅)alkyl. The variableR⁸ can be methyl.

The amine-oxide surfactant can have the structure:

The amine-oxide surfactant can have the structure:

The amine-oxide surfactant can have the structure:

The demulsifier composition can further include another amine-oxidesurfactant, with the other amine-oxide surfactant having the structure:

Method of Treating Produced Petroleum Including an Emulsion.

In various embodiments, the present invention provides a method oftreating a produced petroleum including an emulsion. The method caninclude contacting the produced petroleum with an embodiment of thedemulsifier composition described herein, such that the emulsion in theproduced petroleum is reduced or eliminated. For example, thedemulsifier composition can include an alkanolamide surfactant that is a(C₁-C₅₀)hydrocarbyl amide having groups R¹ and R² substituted on theamide nitrogen, wherein R¹ and R² are each independently selected fromthe group consisting of —H, —(C₁-C₅₀)hydrocarbyl, and—(C₁-C₅₀)hydrocarbylene-OH, wherein at least one of R¹ and R² is—(C₁-C₅₀)hydrocarbylene-OH. The demulsifier composition can include analkoxylated alcohol surfactant that is a (C₁-C₅₀)hydrocarbyl-OH having a—((C₂-C₃)alkylene-O)_(n)—H group on the —OH group, wherein n is about 1to about 100. The demulsifier composition can include an amine-oxidesurfactant. At each occurrence the (C₁-C₅₀)hydrocarbyl and(C₁-C₅₀)hydrocarbylene can be substituted or unsubstituted and areindependently selected.

Other Components.

The demulsifier composition or a mixture including the demulsifiercomposition (e.g., a subterranean treatment fluid including thedemulsifier composition, or another mixture) can include any suitableadditional component in any suitable proportion, such that thedemulsifier composition or mixture including the same can be used asdescribed herein. Any component listed in this section can be present ornot present in the demulsifier composition or a mixture including thesame.

In some embodiments, the demulsifier composition or a mixture includingthe same includes one or more viscosifiers. The viscosifier can be anysuitable viscosifier. The viscosifier can affect the viscosity of thedemulsifier composition or a solvent that contacts the demulsifiercomposition at any suitable time and location. In some embodiments, theviscosifier provides an increased viscosity at least one of beforeinjection into the subterranean formation, at the time of injection intothe subterranean formation, during travel through a tubular disposed ina borehole, once the demulsifier composition reaches a particularsubterranean location, or some period of time after the demulsifiercomposition reaches a particular subterranean location. In someembodiments, the viscosifier can be about 0.000.1 wt % to about 10 wt %of the demulsifier composition or a mixture including the same, about0.004 wt % to about 0.01 wt %, or about 0.000.1 wt % or less, or lessthan, equal to, or greater than about 0.000.5 wt %, 0.001, 0.005, 0.01,0.05, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, or about 10 wt % or more ofthe demulsifier composition or a mixture including the same.

The viscosifier can include at least one of a substituted orunsubstituted polysaccharide, and a substituted or unsubstitutedpolyalkene (e.g., a polyethylene, wherein the ethylene unit issubstituted or unsubstituted, derived from the corresponding substitutedor unsubstituted ethene), wherein the polysaccharide or polyalkene iscrosslinked or uncrosslinked. The viscosifier can include a polymerincluding at least one repeating unit derived from a monomer selectedfrom the group consisting of ethylene glycol, acrylamide, vinyl acetate,2-acrylamidomethylpropane sulfonic acid or its salts,trimethylammoniumethyl acrylate halide, and trimethylammoniumethylmethacrylate halide. The viscosifier can include a crosslinked gel or acrosslinkable gel. The viscosifier can include at least one of a linearpolysaccharide, and a poly((C₂-C₁₀)alkene), wherein the (C₂-C₁₀)alkeneis substituted or unsubstituted. The viscosifier can include at leastone of poly(acrylic acid) or (C₁-C₅)alkyl esters thereof,poly(methacrylic acid) or (C₁-C₅)alkyl esters thereof, poly (vinylacetate), poly(vinyl alcohol), poly(ethylene glycol), poly(vinylpyrrolidone), polyacrylamide, poly (hydroxyethyl methacrylate),alginate, chitosan, curdlan, dextran, derivatized dextran, emulsan, agalactoglucopolysaccharide, gellan, glucuronan, N-acetyl-glucosamine,N-acetyl-heparosan, hyaluronic acid, kefiran, lentinan, levan, mauran,pullulan, scleroglucan, schizophyllan, stewartan, succinoglycan,xanthan, diutan, welan, starch, derivatized starch, tamarind,tragacanth, guar gum, derivatized guar gum (e.g., hydroxypropyl guar,carboxy methyl guar, or carboxymethyl hydroxypropyl guar), gum ghatti,gum arabic, locust bean gum, karaya gum, cellulose, and derivatizedcellulose (e.g., carboxymethyl cellulose, hydroxyethyl cellulose,carboxymethyl hydroxy ethyl cellulose, hydroxypropyl cellulose, ormethyl hydroxy ethyl cellulose).

In some embodiments, the viscosifier can include at least one of apoly(vinyl alcohol) homopolymer, poly(vinyl alcohol) copolymer, acrosslinked poly(vinyl alcohol) homopolymer, and a crosslinkedpoly(vinyl alcohol) copolymer. The viscosifier can include a poly(vinylalcohol) copolymer or a crosslinked poly(vinyl alcohol) copolymerincluding at least one of a graft, linear, branched, block, and randomcopolymer of vinyl alcohol and at least one of a substituted orunsubstituted (C₂-C₅₀)hydrocarbyl having at least one aliphaticunsaturated C—C bond therein, and a substituted or unsubstituted(C₂-C₅₀)alkene. The viscosifier can include a poly(vinyl alcohol)copolymer or a crosslinked poly(vinyl alcohol) copolymer including atleast one of a graft, linear, branched, block, and random copolymer ofvinyl alcohol and at least one of vinyl phosphonic acid, vinylidenediphosphonic acid, substituted or unsubstituted2-acrylamido-2-methylpropanesulfonic acid, a substituted orunsubstituted (C₁-C₂₀)alkenoic acid, propenoic acid, butenoic acid,pentenoic acid, hexenoic acid, octenoic acid, nonenoic acid, decenoicacid, acrylic acid, methacrylic acid, hydroxypropyl acrylic acid,acrylamide, fumaric acid, methacrylic acid, hydroxypropyl acrylic acid,vinyl phosphonic acid, vinylidene diphosphonic acid, itaconic acid,crotonic acid, mesoconic acid, citraconic acid, styrene sulfonic acid,allyl sulfonic acid, methallyl sulfonic acid, vinyl sulfonic acid, and asubstituted or unsubstituted (C₁-C₂₀)alkyl ester thereof. Theviscosifier can include a poly(vinyl alcohol) copolymer or a crosslinkedpoly(vinyl alcohol) copolymer including at least one of a graft, linear,branched, block, and random copolymer of vinyl alcohol and at least oneof vinyl acetate, vinyl propanoate, vinyl butanoate, vinyl pentanoate,vinyl hexanoate, vinyl 2-methyl butanoate, vinyl 3-ethylpentanoate,vinyl 3-ethylhexanoate, maleic anhydride, a substituted or unsubstituted(C₁-C₂₀)alkenoic substituted or unsubstituted (C₁-C₂₀)alkanoicanhydride, a substituted or unsubstituted (C₁-C₂₀)alkenoic substitutedor unsubstituted (C₁-C₂₀)alkenoic anhydride, propenoic acid anhydride,butenoic acid anhydride, pentenoic acid anhydride, hexenoic acidanhydride, octenoic acid anhydride, nonenoic acid anhydride, decenoicacid anhydride, acrylic acid anhydride, fumaric acid anhydride,methacrylic acid anhydride, hydroxypropyl acrylic acid anhydride, vinylphosphonic acid anhydride, vinylidene diphosphonic acid anhydride,itaconic acid anhydride, crotonic acid anhydride, mesoconic acidanhydride, citraconic acid anhydride, styrene sulfonic acid anhydride,allyl sulfonic acid anhydride, methallyl sulfonic acid anhydride, vinylsulfonic acid anhydride, and an N—(C₁-C₁₀)alkenyl nitrogen-containingsubstituted or unsubstituted (C₁-C₁₀)heterocycle. The viscosifier caninclude a poly(vinyl alcohol) copolymer or a crosslinked poly(vinylalcohol) copolymer including at least one of a graft, linear, branched,block, and random copolymer that includes apoly(vinylalcohol/acrylamide) copolymer, apoly(vinylalcohol/2-acrylamido-2-methylpropanesulfonic acid) copolymer,a poly (acrylamide/2-acrylamido-2-methylpropanesulfonic acid) copolymer,or a poly(vinylalcohol/N-vinylpyrrolidone) copolymer. The viscosifiercan include a crosslinked poly(vinyl alcohol) homopolymer or copolymerincluding a crosslinker including at least one of chromium, aluminum,antimony, zirconium, titanium, calcium, boron, iron, silicon, copper,zinc, magnesium, and an ion thereof. The viscosifier can include acrosslinked poly(vinyl alcohol) homopolymer or copolymer including acrosslinker including at least one of an aldehyde, an aldehyde-formingcompound, a carboxylic acid or an ester thereof, a sulfonic acid or anester thereof, a phosphonic acid or an ester thereof, an acid anhydride,and an epihalohydrin.

In various embodiments, the demulsifier composition or a mixtureincluding the same can include one or more crosslinkers. The crosslinkercan be any suitable crosslinker. In some examples, the crosslinker canbe incorporated in a crosslinked viscosifier, and in other examples, thecrosslinker can crosslink a crosslinkable material (e.g., downhole). Thecrosslinker can include at least one of chromium, aluminum, antimony,zirconium, titanium, calcium, boron, iron, silicon, copper, zinc,magnesium, and an ion thereof. The crosslinker can include at least oneof boric acid, borax, a borate, a (C₁-C₃₀)hydrocarbyl boronic acid, a(C₁-C₃₀)hydrocarbyl ester of a (C₁-C₃₀)hydrocarbyl boronic acid, a(C₁-C₃₀)hydrocarbyl boronic acid-modified polyacrylamide, ferricchloride, disodium octaborate tetrahydrate, sodium metaborate, sodiumdiborate, sodium tetraborate, disodium tetraborate, a pentaborate,ulexite, colemanite, magnesium oxide, zirconium lactate, zirconiumtriethanol amine, zirconium lactate triethanolamine, zirconiumcarbonate, zirconium acetylacetonate, zirconium malate, zirconiumcitrate, zirconium diisopropylamine lactate, zirconium glycolate,zirconium triethanol amine glycolate, zirconium lactate glycolate,titanium lactate, titanium malate, titanium citrate, titanium ammoniumlactate, titanium triethanolamine, titanium acetylacetonate, aluminumlactate, and aluminum citrate. In some embodiments, the crosslinker canbe a (C₁-C₂₀)alkylenebiacrylamide (e.g., methylenebisacrylamide), apoly((C₁-C₂₀)alkenyl)-substituted mono- or poly-(C₁-C₂₀)alkyl ether(e.g., pentaerythritol allyl ether), and a poly(C₂-C₂₀)alkenylbenzene(e.g., divinylbenzene). In some embodiments, the crosslinker can be atleast one of alkyl diacrylate, ethylene glycol diacrylate, ethyleneglycol dimethacrylate, polyethylene glycol diacrylate, polyethyleneglycol dimethacrylate, ethoxylated bisphenol A diacrylate, ethoxylatedbisphenol A dimethacrylate, ethoxylated trimethylol propane triacrylate,ethoxylated trimethylol propane trimethacrylate, ethoxylated glyceryltriacrylate, ethoxylated glyceryl trimethacrylate, ethoxylatedpentaerythritol tetraacrylate, ethoxylated pentaerythritoltetramethacrylate, ethoxylated dipentaerythritol hexaacrylate,polyglyceryl monoethylene oxide polyacrylate, polyglyceryl polyethyleneglycol polyacrylate, dipentaerythritol hexaacrylate, dipentaerythritolhexamethacrylate, neopentyl glycol diacrylate, neopentyl glycoldimethacrylate, pentaerythritol triacrylate, pentaerythritoltrimethacrylate, trimethylol propane triacrylate, trimethylol propanetrimethacrylate, tricyclodecane dimethanol diacrylate, tricyclodecanedimethanol dimethacrylate, 1,6-hexanediol diacrylate, and 1,6-hexanedioldimethacrylate. The crosslinker can be about 0.000.01 wt % to about 5 wt% of the demulsifier composition or a mixture including the same, about0.001 wt % to about 0.01 wt %, or about 0.000.01 wt % or less, or lessthan, equal to, or greater than about 0.000.05 wt %, 0.000,1, 0.000,5,0.001, 0.005, 0.01, 0.05, 0.1, 0.5, 1, 2, 3, 4, or about 5 wt % or more.

In some embodiments, the demulsifier composition or a mixture includingthe same can include one or more breakers. The breaker can be anysuitable breaker, such that the surrounding fluid (e.g., a fracturingfluid) can be at least partially broken for more complete and moreefficient recovery thereof, such as at the conclusion of the hydraulicfracturing treatment. In some embodiments, the breaker can beencapsulated or otherwise formulated to give a delayed-release or atime-release of the breaker, such that the surrounding liquid can remainviscous for a suitable amount of time prior to breaking. The breaker canbe any suitable breaker; for example, the breaker can be a compound thatincludes at least one of a Na⁺, K⁺, Li⁺, Zn⁺, NH₄ ⁺, Fe²⁺, Fe³⁺, Cu¹⁺,Cu²⁺, Ca²⁺, Mg²⁺, Zn²⁺, and an Al³⁺ salt of a chloride, fluoride,bromide, phosphate, or sulfate ion. In some examples, the breaker can bean oxidative breaker or an enzymatic breaker. An oxidative breaker canbe at least one of aNa⁺, K⁺, Li⁺, Zn⁺, NH₄ ⁺, Fe²⁺, Fe³⁺, Cu¹⁺, Cu²⁺,Ca²⁺, Mg²⁺, Zn²⁺, and an Al³⁺ salt of a persulfate, percarbonate,perborate, peroxide, perphosphosphate, permanganate, chlorite, orhypochlorite ion. An enzymatic breaker can be at least one of an alphaor beta amylase, amyloglucosidase, oligoglucosidase, invertase, maltase,cellulase, hemi-cellulase, and mannanohydrolase. The breaker can beabout 0.001 wt % to about 30 wt % of the demulsifier composition or amixture including the same, or about 0.01 wt % to about 5 wt %, or about0.001 wt % or less, or less than, equal to, or greater than about 0.005wt %, 0.01, 0.05, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 8, 10, 12, 14, 16, 18, 20,22, 24, 26, 28, or about 30 wt % or more.

The demulsifier composition, or a mixture including the demulsifiercomposition, can include any suitable fluid. For example, the fluid canbe at least one of crude oil, dipropylene glycol methyl ether,dipropylene glycol dimethyl ether, dipropylene glycol methyl ether,dipropylene glycol dimethyl ether, dimethyl formamide, diethylene glycolmethyl ether, ethylene glycol butyl ether, diethylene glycol butylether, butylglycidyl ether, propylene carbonate, D-limonene, a C₂-C₄₀fatty acid C₁-C₁₀ alkyl ester (e.g., a fatty acid methyl ester),tetrahydrofurfuryl methacrylate, tetrahydrofurfuryl acrylate, 2-butoxyethanol, butyl acetate, butyl lactate, furfuryl acetate, dimethylsulfoxide, dimethyl formamide, a petroleum distillation product offraction (e.g., diesel, kerosene, napthas, and the like) mineral oil,ahydrocarbon oil, ahydrocarbon including an aromatic carbon-carbon bond(e.g., benzene, toluene), ahydrocarbon including an alpha olefin,xylenes, an ionic liquid, methyl ethyl ketone, an ester of oxalic,maleic or succinic acid, methanol, ethanol, propanol (iso- or normal-),butyl alcohol (iso-, tert-, or normal-), an aliphatic hydrocarbon (e.g.,cyclohexanone, hexane), water, brine, produced water, flowback water,brackish water, and sea water. The fluid can form about 0.001 wt % toabout 99.999 wt % of the demulsifier composition, or a mixture includingthe same, or about 0.001 wt % or less, or less than, equal to, orgreater than about 0.01 wt %, 0.1, 1, 2, 3, 4, 5, 6, 8, 10, 15, 20, 25,30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 96, 97, 98, 99,99.9, 99.99, or about 99.999 wt % or more.

A mixture including the demulsifier composition can include any suitabledownhole fluid. The demulsifier composition can be combined with anysuitable downhole fluid before, during, or after the placement of thedemulsifier composition in the subterranean formation or the contactingof the demulsifier composition and the subterranean material. In someexamples, the demulsifier composition is combined with a downhole fluidabove the surface, and then the combined composition is placed in asubterranean formation or contacted with a subterranean material. Inanother example, the demulsifier composition is injected into asubterranean formation to combine with a downhole fluid, and thecombined composition is contacted with a subterranean material or isconsidered to be placed in the subterranean formation. The placement ofthe demulsifier composition in the subterranean formation can includecontacting the subterranean material and the mixture. Any suitableweight percent of a mixture including the demulsifier composition thatis placed in the subterranean formation or contacted with thesubterranean material can be the downhole fluid, such as about 0.001 wt% to about 99.999 wt %, about 0.01 wt % to about 99.99 wt %, about 0.1wt % to about 99.9 wt %, about 20 wt % to about 90 wt %, or about 0.001wt % or less, or less than, equal to, or greater than about 0.01 wt %,0.1, 1, 2, 3, 4, 5, 10, 15, 20, 30, 40, 50, 60, 70, 80, 85, 90, 91, 92,93, 94, 95, 96, 97, 98, 99, 99.9, 99.99 wt %, or about 99.999 wt % ormore of the demulsifier composition or mixture including the same.

In some embodiments, the demulsifier composition, or a mixture includingthe same, can include any suitable amount of any suitable material usedin a downhole fluid. For example, the demulsifier composition or amixture including the same can include water, saline, aqueous base,acid, oil, organic solvent, synthetic fluid oil phase, aqueous solution,alcohol or polyol, cellulose, starch, alkalinity control agents, aciditycontrol agents, density control agents, density modifiers, emulsifiers,dispersants, polymeric stabilizers, polyacrylamide, a polymer orcombination of polymers, antioxidants, heat stabilizers, foam controlagents, solvents, diluents, plasticizer, filler or inorganic particle,pigment, dye, precipitating agent, oil-wetting agents, set retardingadditives, surfactants, gases, weight reducing additives, heavy-weightadditives, lost circulation materials, filtration control additives,salts (e.g., any suitable salt, such as potassium salts such aspotassium chloride, potassium bromide, potassium formate; calcium saltssuch as calcium chloride, calcium bromide, calcium formate; cesium saltssuch as cesium chloride, cesium bromide, cesium formate, or acombination thereof), fibers, thixotropic additives, breakers,crosslinkers, rheology modifiers, curing accelerators, curing retarders,pH modifiers, chelating agents, scale inhibitors, enzymes, resins, watercontrol materials, disproportionate permeability modifiers, relativepermeability modifiers, oxidizers, markers, Portland cement, pozzolanacement, gypsum cement, high alumina content cement, slag cement, sorelcement (e.g., Mg₄Cl₂(OH)₆(H₂O)₈), micro matrix cement, silica cement,fly ash, metakaolin, shale, zeolite, a crystalline silica compound,amorphous silica, hydratable clays, microspheres, lime, or a combinationthereof. In various embodiments, the demulsifier composition or amixture including the same can include one or more additive componentssuch as: COLDTROL®, ATC®, OMC 2™, and OMC 42™ thinner additives; RHEMOD™viscosifier and suspension agent; TEMPERUS™ and VIS-PLUS® additives forproviding temporary increased viscosity; TAU-MOD™viscosifying/suspension agent; ADAPTA®, DURATONE® HT, THERMO TONE™,BDF™-366, and BDF™-454 filtration control agents; LIQUITONE™ polymericfiltration agent and viscosifier; FACTANT™ emulsion stabilizer; LESUPERMUL™, EZ MUL® NT, and FORTI-MUL® emulsifiers; DRIL TREAT® oilwetting agent for heavy fluids; AQUATONE-S™ wetting agent; BARACARB®bridging agent; BAROID® weighting agent; BAROLIFT® hole sweeping agent;SWEEP-WATE® sweep weighting agent; BDF-508 rheology modifier; andGELTONE® II organophilic clay. In various embodiments, the demulsifiercomposition or a mixture including the same can include one or moreadditive components such as: X-TEND® II, PAC™-R, PAC™-L, LIQUI-VIS® EP,BRINEDRIL-VIS™, BARAZAN®, N-VIS®, and AQUAGEL® viscosifiers;THERMA-CHEK®, N-DRIL™, N-DRIL™ HT PLUS, IMPERMEX®, FILTERCHEK™,DEXTRID®, CARBONOX®, and BARANEX® filtration control agents;PERFORMATROL®, GEM™, EZ-MUD®, CLAY GRABBER®, CLAYSEAL®, CRYSTAL-DRIL®,and CLAY SYNC™ II shale stabilizers; NXS-LUBE™, EP MUDLUBE®, andDRIL-N-SLIDE™ lubricants; QUIK-THIN®, IRON-THIN™, THERMA-THIN®, andENVIRO-THIN™ thinners; SOURSCAV™ scavenger; BARACOR® corrosioninhibitor; and WALL-NUT®, SWEEP-WATE®, STOPPIT™, PLUG-GIT®, BARACARB®,DUO-SQUEEZE®, BAROFIBRE™, STEELSEAL®, and HYDRO-PLUG® lost circulationmanagement materials. Any suitable proportion of the demulsifiercomposition or mixture including the demulsifier composition can includeany optional component listed in this paragraph, such as about 0.001 wt% to about 99.999 wt %, about 0.01 wt % to about 99.99 wt %, about 0.1wt % to about 99.9 wt %, about 20 to about 90 wt %, or about 0.001 wt %or less, or less than, equal to, or greater than about 0.01 wt %, 0.1,1, 2, 3, 4, 5, 10, 15, 20, 30, 40, 50, 60, 70, 80, 85, 90, 91, 92, 93,94, 95, 96, 97, 98, 99, 99.9, 99.99 wt %, or about 99.999 wt % or moreof the demulsifier composition or mixture.

A drilling fluid, also known as a drilling mud or simply “mud,” is aspecially designed fluid that is circulated through a wellbore as thewellbore is being drilled to facilitate the drilling operation. Thedrilling fluid can be water-based or oil-based. The drilling fluid cancarry cuttings up from beneath and around the bit, transport them up theannulus, and allow their separation. Also, a drilling fluid can cool andlubricate the drill bit as well as reduce friction between the drillstring and the sides of the hole. The drilling fluid aids in support ofthe drill pipe and drill bit, and provides a hydrostatic head tomaintain the integrity of the wellbore walls and prevent well blowouts.Specific drilling fluid systems can be selected to optimize a drillingoperation in accordance with the characteristics of a particulargeological formation. The drilling fluid can be formulated to preventunwanted influxes of formation fluids from permeable rocks and also toform a thin, low permeability filter cake that temporarily seals pores,other openings, and formations penetrated by the bit. In water-baseddrilling fluids, solid particles are suspended in a water or brinesolution containing other components. Oils or other non-aqueous liquidscan be emulsified in the water or brine or at least partiallysolubilized (for less hydrophobic non-aqueous liquids), but water is thecontinuous phase. A mixture including the demulsifier composition caninclude a drilling fluid in any suitable amount, such as about 1 wt % orless, or less than, equal to, or greater than about 2 wt %, 3, 4, 5, 10,15, 20, 30, 40, 50, 60, 70, 80, 85, 90, 95, 96, 97, 98, 99, 99.9, 99.99,or about 99.999 wt % or more.

A water-based drilling fluid in embodiments of the present invention canbe any suitable water-based drilling fluid. In various embodiments, thedrilling fluid can include at least one of water (fresh or brine), asalt (e.g., calcium chloride, sodium chloride, potassium chloride,magnesium chloride, calcium bromide, sodium bromide, potassium bromide,calcium nitrate, sodium formate, potassium formate, cesium formate),aqueous base (e.g., sodium hydroxide or potassium hydroxide), alcohol orpolyol, cellulose, starches, alkalinity control agents, density controlagents such as a density modifier (e.g., barium sulfate), surfactants(e.g., betaines, alkali metal alkylene acetates, sultaines, ethercarboxylates), emulsifiers, dispersants, polymeric stabilizers,crosslinking agents, polyacrylamides, polymers or combinations ofpolymers, antioxidants, heat stabilizers, foam control agents, solvents,diluents, plasticizers, filler or inorganic particles (e.g., silica),pigments, dyes, precipitating agents (e.g., silicates or aluminumcomplexes), and rheology modifiers such as thickeners or viscosifiers(e.g., xanthan gum, laponite gels, geltones, sepiolite gel, TAU-MOD®).Any ingredient listed in this paragraph can be either present or notpresent in the mixture.

An oil-based drilling fluid or mud in embodiments of the presentinvention can be any suitable oil-based drilling fluid. In variousembodiments, the drilling fluid can include at least one of an oil-basedfluid (or synthetic fluid), saline, aqueous solution, emulsifiers, otheragents or additives for suspension control, weight or density control,oil-wetting agents, fluid loss or filtration control agents, andrheology control agents. An oil-based or invert emulsion-based drillingfluid can include between about 10:90 to about 95:5, or about 50:50 toabout 95:5, by volume of oil phase to water phase. A substantially alloil mud includes about 100% liquid phase oil by volume (e.g.,substantially no internal aqueous phase).

A pill is a relatively small quantity (e.g., less than about 500 bbl, orless than about 200 bbl) of drilling fluid used to accomplish a specifictask that the regular drilling fluid cannot perform. For example, a pillcan be a high-viscosity pill to, for example, help lift cuttings out ofa vertical wellbore. In another example, a pill can be a freshwater pillto, for example, dissolve a salt formation. Another example is apipe-freeing pill to, for example, destroy filter cake and relievedifferential sticking forces. In another example, a pill is a lostcirculation material pill to, for example, plug a thief zone. A pill caninclude any component described herein as a component of a drillingfluid.

A cement fluid can include an aqueous mixture of at least one of cementand cement kiln dust. The demulsifier composition can form a usefulcombination with cement or cement kiln dust. The cement kiln dust can beany suitable cement kiln dust. Cement kiln dust can be formed during themanufacture of cement and can be partially calcined kiln feed that isremoved from the gas stream and collected in a dust collector during amanufacturing process. Cement kiln dust can be advantageously utilizedin a cost-effective manner since kiln dust is often regarded as a lowvalue waste product of the cement industry. Some embodiments of thecement fluid can include cement kiln dust but no cement, cement kilndust and cement, or cement but no cement kiln dust. The cement can beany suitable cement. The cement can be a hydraulic cement. A variety ofcements can be utilized in accordance with embodiments of the presentinvention; for example, those including calcium, aluminum, silicon,oxygen, iron, or sulfur, which can set and harden by reaction withwater. Suitable cements can include Portland cements, pozzolana cements,gypsum cements, high alumina content cements, slag cements, sorelcements (e.g., Mg₄Cl₂(OH)₆(H₂O)₈), micro matrix cements, silica cements,and combinations thereof. In some embodiments, the Portland cements thatare suitable for use in embodiments of the present invention areclassified as Classes A, C, H, and G cements according to the AmericanPetroleum Institute, API Specification for Materials and Testing forWell Cements, API Specification 10, Fifth Ed., Jul. 1, 1990. A cementcan be generally included in the cementing fluid in an amount sufficientto provide the desired compressive strength, density, or cost. In someembodiments, the hydraulic cement can be present in the cementing fluidin an amount in the range of from 0 wt % to about 100 wt %, about 0 wt %to about 95 wt %, about 20 wt % to about 95 wt %, or about 50 wt % toabout 90 wt %. A cement kiln dust can be present in an amount of atleast about 0.01 wt %, or about 5 wt % to about 80 wt %, or about 10 wt% to about 50 wt %.

Optionally, other additives can be added to a cement or kilndust-containing composition of embodiments of the present invention asdeemed appropriate by one skilled in the art, with the benefit of thisdisclosure. Any optional ingredient listed in this paragraph can beeither present or not present in the demulsifier composition or amixture including the same. For example, the demulsifier composition caninclude fly ash, metakaolin, shale, zeolite, set retarding additive,surfactant, a gas, accelerators, weight reducing additives, heavy-weightadditives, lost circulation materials, filtration control additives,dispersants, and combinations thereof. In some examples, additives caninclude crystalline silica compounds, amorphous silica, salts, fibers,hydratable clays, microspheres, pozzolan lime, thixotropic additives,combinations thereof, and the like.

In various embodiments, the demulsifier composition or mixture includingthe same can include a proppant, a resin-coated proppant, anencapsulated resin, or a combination thereof. A proppant is a materialthat keeps an induced hydraulic fracture at least partially open duringor after a fracturing treatment. Proppants can be transported into thesubterranean formation (e.g., downhole) to the fracture using fluid,such as fracturing fluid or another fluid. A higher-viscosity fluid canmore effectively transport proppants to a desired location in afracture, especially larger proppants, by more effectively keepingproppants in a suspended state within the fluid. Examples of proppantscan include sand, gravel, glass beads, polymer beads, ground productsfrom shells and seeds such as walnut hulls, and manmade materials suchas ceramic proppant, bauxite, tetrafluoroethylene materials (e.g.,TEFLON™ polytetrafluoroethylene), fruit pit materials, processed wood,composite particulates prepared from a binder and fine gradeparticulates such as silica, alumina, fumed silica, carbon black,graphite, mica, titanium dioxide, meta-silicate, calcium silicate,kaolin, talc, zirconia, boron, fly ash, formation cuttings (e.g.,reinjected), hollow glass microspheres, and solid glass, or mixturesthereof. In some embodiments, the proppant can have an average particlesize, wherein particle size is the largest dimension of a particle, ofabout 0.001 mm to about 3 mm, about 0.15 mm to about 2.5 mm, about 0.25mm to about 0.43 mm, about 0.43 mm to about 0.85 mm, about 0.0001 mm toabout 3 mm, about 0.015 mm to about 2.5 mm, about 0.025 mm to about 0.43mm, about 0.043 mm to about 0.85 mm, about 0.085 mm to about 1.18 mm,about 0.85 mm to about 1.18 mm, about 1.18 mm to about 1.70 mm, or about1.70 to about 2.36 mm. In some embodiments, the proppant can have adistribution of particle sizes clustering around multiple averages, suchas one, two, three, or four different average particle sizes. Thedemulsifier composition or mixture can include any suitable amount ofproppant, such as about 0.01 wt % to about 99.99 wt %, about 0.1 wt % toabout 80 wt %, about 10 wt % to about 60 wt %, or about 0.01 wt % orless, or less than, equal to, or greater than about 0.1 wt %, 1, 2, 3,4, 5, 10, 15, 20, 30, 40, 50, 60, 70, 80, 85, 90, 91, 92, 93, 94, 95,96, 97, 98, 99, about 99.9 wt %, or about 99.99 wt % or more.

Drilling Assembly.

In various embodiments, the demulsifier composition disclosed herein candirectly or indirectly affect one or more components or pieces ofequipment associated with the preparation, delivery, recapture,recycling, reuse, and/or disposal of the demulsifier composition. Forexample, and with reference to FIG. 1, the demulsifier composition candirectly or indirectly affect one or more components or pieces ofequipment associated with an exemplary wellbore drilling assembly 100,according to one or more embodiments. It should be noted that while FIG.1 generally depicts a land-based drilling assembly, those skilled in theart will readily recognize that the principles described herein areequally applicable to subsea drilling operations that employ floating orsea-based platforms and rigs, without departing from the scope of thedisclosure.

As illustrated, the drilling assembly 100 can include a drillingplatform 102 that supports a derrick 104 having a traveling block 106for raising and lowering a drill string 108. The drill string 108 caninclude drill pipe and coiled tubing, as generally known to thoseskilled in the art. A kelly 110 supports the drill string 108 as it islowered through a rotary table 112. A drill bit 114 is attached to thedistal end of the drill string 108 and is driven either by a downholemotor and/or via rotation of the drill string 108 from the well surface.As the bit 114 rotates, it creates a wellbore 116 that penetratesvarious subterranean formations 118.

A pump 120 (e.g., a mud pump) circulates drilling fluid 122 through afeed pipe 124 and to the kelly 110, which conveys the drilling fluid 122downhole through the interior of the drill string 108 and through one ormore orifices in the drill bit 114. The drilling fluid 122 is thencirculated back to the surface via an annulus 126 defined between thedrill string 108 and the walls of the wellbore 116. At the surface, therecirculated or spent drilling fluid 122 exits the annulus 126 and canbe conveyed to one or more fluid processing unit(s) 128 via aninterconnecting flow line 130. After passing through the fluidprocessing unit(s) 128, a “cleaned” drilling fluid 122 is deposited intoa nearby retention pit 132 (e.g., a mud pit). While the fluid processingunit(s) 128 is illustrated as being arranged at the outlet of thewellbore 116 via the annulus 126, those skilled in the art will readilyappreciate that the fluid processing unit(s) 128 can be arranged at anyother location in the drilling assembly 100 to facilitate its properfunction, without departing from the scope of the disclosure.

The demulsifier composition can be added to the drilling fluid 122 via amixing hopper 134 communicably coupled to or otherwise in fluidcommunication with the retention pit 132. The mixing hopper 134 caninclude mixers and related mixing equipment known to those skilled inthe art. In other embodiments, however, the demulsifier composition canbe added to the drilling fluid 122 at any other location in the drillingassembly 100. In at least one embodiment, for example, there could bemore than one retention pit 132, such as multiple retention pits 132 inseries. Moreover, the retention pit 132 can be representative of one ormore fluid storage facilities and/or units where the demulsifiercomposition can be stored, reconditioned, and/or regulated until addedto the drilling fluid 122.

As mentioned above, the demulsifier composition can directly orindirectly affect the components and equipment of the drilling assembly100. For example, the demulsifier composition can directly or indirectlyaffect the fluid processing unit(s) 128, which can include one or moreof a shaker (e.g., shale shaker), a centrifuge, a hydrocyclone, aseparator (including magnetic and electrical separators), a desilter, adesander, a separator, a filter (e.g., diatomaceous earth filters), aheat exchanger, or any fluid reclamation equipment. The fluid processingunit(s) 128 can further include one or more sensors, gauges, pumps,compressors, and the like used to store, monitor, regulate, and/orrecondition the demulsifier composition.

The demulsifier composition can directly or indirectly affect the pump120, which representatively includes any conduits, pipelines, trucks,tubulars, and/or pipes used to fluidically convey the demulsifiercomposition to the subterranean formation; any pumps, compressors, ormotors (e.g., topside or downhole) used to drive the demulsifiercomposition into motion; any valves or related joints used to regulatethe pressure or flow rate of the demulsifier composition; and anysensors (e.g., pressure, temperature, flow rate, and the like), gauges,and/or combinations thereof, and the like. The demulsifier compositioncan also directly or indirectly affect the mixing hopper 134 and theretention pit 132 and their assorted variations.

The demulsifier composition can also directly or indirectly affect thevarious downhole or subterranean equipment and tools that can come intocontact with the demulsifier composition such as the drill string 108,any floats, drill collars, mud motors, downhole motors, and/or pumpsassociated with the drill string 108, and any measurement while drilling(MWD)/logging while drilling (LWD) tools and related telemetryequipment, sensors, or distributed sensors associated with the drillstring 108. The demulsifier composition can also directly or indirectlyaffect any downhole heat exchangers, valves, and corresponding actuationdevices, tool seals, packers, other wellbore isolation devices orcomponents, and the like associated with the wellbore 116. Thedemulsifier composition can also directly or indirectly affect the drillbit 114, which can include roller cone bits, poly crystalline diamondcompact (PDC) bits, natural diamond bits, hole openers, reamers, coringbits, and the like.

While not specifically illustrated herein, the demulsifier compositioncan also directly or indirectly affect any transport or deliveryequipment used to convey the demulsifier composition to the drillingassembly 100 such as, for example, any transport vessels, conduits,pipelines, trucks, tubulars, and/or pipes used to fluidically move thedemulsifier composition from one location to another; any pumps,compressors, or motors used to drive the demulsifier composition intomotion; any valves or related joints used to regulate the pressure orflow rate of the demulsifier composition; and any sensors (e.g.,pressure and temperature), gauges, and/or combinations thereof, and thelike.

System or Apparatus.

In various embodiments, the present invention provides a system. Thesystem can be any suitable system that can use or that can be generatedby use of an embodiment of the demulsifier composition described hereinin a subterranean formation, or that can perform or be generated byperformance of a method for using the demulsifier composition describedherein. The system can include a demulsifier composition, such as anydemulsifier composition described herein. The system can also include asubterranean formation including the demulsifier composition therein. Insome embodiments, the demulsifier composition in the system can alsoinclude a downhole fluid, or the system can include a mixture of thedemulsifier composition and downhole fluid. In some embodiments, thesystem can include a tubular, and a pump configured to pump thedemulsifier composition into the subterranean formation through thetubular.

In some embodiments, the system can include a tubular disposed in asubterranean formation. The system can also include a pump configured topump a demulsifier composition in the subterranean formation through thetubular. The demulsifier composition can include an alkanolamidesurfactant that is a (C₁-C₅₀)hydrocarbyl amide having groups R¹ and R²substituted on the amide nitrogen, wherein R¹ and R² are eachindependently selected from the group consisting of —H,—(C₁-C₅₀)hydrocarbyl, and —(C₁-C₅₀)hydrocarbylene-OH, wherein at leastone of R¹ and R² is —(C₁-C₅₀)hydrocarbylene-OH. The demulsifiercomposition can include an alkoxylated alcohol surfactant that is a(C₁-C₅₀)hydrocarbyl-OH having a —((C₂-C₃)alkylene-O)_(n)—H group on the—OH group, wherein n is about 1 to about 100. The demulsifiercomposition can include an amine-oxide surface. At each occurrence the(C₁-C₅₀)hydrocarbyl and (C₁-C₅₀)hydrocarbylene are substituted orunsubstituted and are independently selected.

Various embodiments provide systems and apparatus configured fordelivering the demulsifier composition described herein to asubterranean location and for using the demulsifier composition therein,such as for a drilling operation, or a fracturing operation (e.g.,pre-pad, pad, slurry, or finishing stages). In various embodiments, thesystem or apparatus can include a pump fluidly coupled to a tubular(e.g., any suitable type of oilfield pipe, such as pipeline, drill pipe,production tubing, and the like), with the tubular containing thedemulsifier composition.

In some embodiments, the system can include a drill string disposed in awellbore, with the drill string including a drill bit at a downhole endof the drill string. The system can also include an annulus between thedrill string and the wellbore. The system can also include a pumpconfigured to circulate the demulsifier composition through the drillstring, through the drill bit, and back above-surface through theannulus. In some embodiments, the system can include a fluid processingunit configured to process the demulsifier composition exiting theannulus to generate a cleaned drilling fluid for recirculation throughthe wellbore.

The pump can be a high pressure pump in some embodiments. As usedherein, the term “high pressure pump” will refer to a pump that iscapable of delivering a fluid to a subterranean formation (e.g.,downhole) at a pressure of about 1000 psi or greater. A high pressurepump can be used when it is desired to introduce the demulsifiercomposition to a subterranean formation at or above a fracture gradientof the subterranean formation, but it can also be used in cases wherefracturing is not desired. In some embodiments, the high pressure pumpcan be capable of fluidly conveying particulate matter, such as proppantparticulates, into the subterranean formation. Suitable high pressurepumps will be known to one having ordinary skill in the art and caninclude floating piston pumps and positive displacement pumps.

In other embodiments, the pump can be a low pressure pump. As usedherein, the term “low pressure pump” will refer to a pump that operatesat a pressure of about 1000 psi or less. In some embodiments, a lowpressure pump can be fluidly coupled to a high pressure pump that isfluidly coupled to the tubular. That is, in such embodiments, the lowpressure pump can be configured to convey the demulsifier composition tothe high pressure pump. In such embodiments, the low pressure pump can“step up” the pressure of the demulsifier composition before it reachesthe high pressure pump.

In some embodiments, the systems or apparatuses described herein canfurther include a mixing tank that is upstream of the pump and in whichthe demulsifier composition is formulated. In various embodiments, thepump (e.g., a low pressure pump, a high pressure pump, or a combinationthereof) can convey the demulsifier composition from the mixing tank orother source of the demulsifier composition to the tubular. In otherembodiments, however, the demulsifier composition can be formulatedoffsite and transported to a worksite, in which case the demulsifiercomposition can be introduced to the tubular via the pump directly fromits shipping container (e.g., a truck, a railcar, a barge, or the like)or from a transport pipeline. In either case, the demulsifiercomposition can be drawn into the pump, elevated to an appropriatepressure, and then introduced into the tubular for delivery to thesubterranean formation.

FIG. 2 shows an illustrative schematic of systems and apparatuses thatcan deliver embodiments of the demulsifier compositions of the presentinvention to a subterranean location, according to one or moreembodiments. It should be noted that while FIG. 2 generally depicts aland-based system or apparatus, it is to be recognized that like systemsand apparatuses can be operated in subsea locations as well. Embodimentsof the present invention can have a different scale than that depictedin FIG. 2. As depicted in FIG. 2, system or apparatus 1 can includemixing tank 10, in which an embodiment of the demulsifier compositioncan be formulated. The demulsifier composition can be conveyed via line12 to wellhead 14, where the demulsifier composition enters tubular 16,with tubular 16 extending from wellhead 14 into subterranean formation18. Upon being ejected from tubular 16, the demulsifier composition cansubsequently penetrate into subterranean formation 18. Pump 20 can beconfigured to raise the pressure of the demulsifier composition to adesired degree before its introduction into tubular 16. It is to berecognized that system or apparatus 1 is merely exemplary in nature andvarious additional components can be present that have not necessarilybeen depicted in FIG. 2 in the interest of clarity. In some examples,additional components that can be present include supply hoppers,valves, condensers, adapters, joints, gauges, sensors, compressors,pressure controllers, pressure sensors, flow rate controllers, flow ratesensors, temperature sensors, and the like.

Although not depicted in FIG. 2, at least part of the demulsifiercomposition can, in some embodiments, flow back to wellhead 14 and exitsubterranean formation 18. In some embodiments, the demulsifiercomposition that has flowed back to wellhead 14 can subsequently berecovered, and in some examples reformulated, and recirculated tosubterranean formation 18.

It is also to be recognized that the disclosed composition can alsodirectly or indirectly affect the various downhole or subterraneanequipment and tools that can come into contact with the demulsifiercomposition during operation. Such equipment and tools can includewellbore casing, wellbore liner, completion string, insert strings,drill string, coiled tubing, slickline, wireline, drill pipe, drillcollars, mud motors, downhole motors and/or pumps, surface-mountedmotors and/or pumps, centralizers, turbolizers, scratchers, floats(e.g., shoes, collars, valves, and the like), logging tools and relatedtelemetry equipment, actuators (e.g., electromechanical devices,hydromechanical devices, and the like), sliding sleeves, productionsleeves, plugs, screens, filters, flow control devices (e.g., inflowcontrol devices, autonomous inflow control devices, outflow controldevices, and the like), couplings (e.g., electro-hydraulic wet connect,dry connect, inductive coupler, and the like), control lines (e.g.,electrical, fiber optic, hydraulic, and the like), surveillance lines,drill bits and reamers, sensors or distributed sensors, downhole heatexchangers, valves and corresponding actuation devices, tool seals,packers, cement plugs, bridge plugs, and other wellbore isolationdevices or components, and the like. Any of these components can beincluded in the systems and apparatuses generally described above anddepicted in FIG. 2

Demulsifier Composition for Treatment of a Subterranean Formation orProduced Petroleum Including an Emulsion.

Various embodiments provide a demulsifier composition. In someembodiments, the demulsifier composition can be for treatment of asubterranean formation. In some embodiments, the demulsifier compositioncan be for treatment of oil produced from a subterranean formation. Thedemulsifier composition can be any suitable composition that can be usedto perform an embodiment of the method for treatment of a subterraneanformation described herein, or an embodiment of the method for treatmentof produced petroleum including an emulsion described herein.

For example, the demulsifier composition can include an alkanolamidesurfactant that is a (C₁-C₅₀)hydrocarbyl amide having groups R¹ and R²substituted on the amide nitrogen, wherein R¹ and R² are eachindependently selected from the group consisting of —H,—(C₁-C₅₀)hydrocarbyl, and —(C₁-C₅₀)hydrocarbylene-OH, wherein at leastone of R¹ and R² is —(C₁-C₅₀)hydrocarbylene-OH. The demulsifiercomposition can include an alkoxylated alcohol surfactant that is a(C₁-C₅₀)hydrocarbyl-OH having a —((C₂-C₃)alkylene-O)_(n)—H group on the—OH group, wherein n is about 1 to about 100. The demulsifiercomposition can also include an amine-oxide surfactant. At eachoccurrence the (C₁-C₅₀)hydrocarbyl and (C₁-C₅₀)hydrocarbylene can besubstituted or unsubstituted and are independently selected.

In some embodiments, the present invention provides a composition thatis a mixture of a downhole fluid and the demulsifier composition. Forexample, a downhole fluid can include the demulsifier composition. Forexample, a hydraulic fracturing fluid can include the demulsifiercomposition.

In some embodiments, the demulsifier composition can include an aqueousphase. The demulsifier composition can include an oil phase, wherein thedemulsifier composition includes an emulsion including the aqueous phaseand the oil phase. The demulsifier composition can include analkanolamide surfactant that has the structure:

The variable R³ can be a substituted or unsubstituted(C₁₂-C₂₅)hydrocarbyl of a tall oil fatty acid having the structureR³—C(O)—OH. The variables R¹ and R² can be each independently—(C₁-C₁₀)alkylene-OH. The demulsifier composition can include analkoxylated alcohol surfactant that is a (C₁₀-C₂₀)hydrocarbon includinga secondary alcohol group, wherein the (C₁₀-C₂₀)hydrocarbon is otherwiseunsubstituted, wherein the secondary alcohol group includes a—(CH₂—CH₂—O)₅₋₁₀—H group thereon. The demulsifier composition caninclude an amine-oxide surfactant having the structure:

The variable R⁶ can be (C₁₁-C₁₃)alkyl. The variable R⁷ can be(C₁-C₅)alkylene. At each occurrence, R⁸ can be independently(C₁-C₅)alkyl.

In various embodiments, the demulsifier composition includes an aqueousphase that can be about 10 wt % to about 80 wt % of the demulsifiercomposition. The demulsifier composition can include an oil phase thatcan be about 10 wt % to about 80 wt % of the demulsifier composition,wherein the demulsifier composition includes an emulsion including theaqueous phase and the oil phase. The demulsifier composition can includea (C₁-C₅)alkyl alcohol that can be about 5 wt % to about 30 wt % of thedemulsifier composition. The demulsifier composition can include analkanolamide surfactant that can be about 5 wt % to about 40 wt % of thedemulsifier composition, wherein the alkanolamide surfactant has thestructure:

The variable R³ can be a substituted or unsubstituted(C₁₅-C₁₇)hydrocarbyl of a tall oil fatty acid having the structureR³—C(O)—OH. The variables R¹ and R² can each be —CH₂—CH₂—OH. Thedemulsifier composition can include an alkoxylated alcohol surfactantthat can be about 5 wt % to about 40 wt % of the demulsifiercomposition, wherein the alkoxylated alcohol surfactant is a(C₁₅)hydrocarbon including a secondary alcohol group, wherein the(C₁₅)hydrocarbon is otherwise unsubstituted, wherein the secondaryalcohol group includes a —(CH₂—CH₂—O)₇—H group thereon. The demulsifiercomposition can include an amine-oxide surfactant that can be about 0.01wt % to about 20 wt % of the demulsifier composition, wherein theamine-oxide surfactant can have the structure:

The demulsifier composition can also include an amine-oxide surfactantthat can be about 0.01 wt % to about 20 wt % of the demulsifiercomposition, wherein the amine-oxide surfactant can have the structure:

Method for Preparing a Demulsifier Composition for Treatment of aSubterranean Formation or of Produced Petroleum Including an Emulsion.

In various embodiments, the present invention provides a method forpreparing a demulsifier composition for treatment of a subterraneanformation or of produced petroleum including an emulsion. The method canbe any suitable method that produces an embodiment of the demulsifiercomposition described herein. For example, the method can includeforming a demulsifier composition including an alkanolamide surfactantthat is a (C₁-C₅₀)hydrocarbyl amide having groups R¹ and R² substitutedon the amide nitrogen, wherein R¹ and R² are each independently selectedfrom the group consisting of —H, —(C₁-C₅₀)hydrocarbyl, and—(C₁-C₅₀)hydrocarbylene-OH, wherein at least one of R¹ and R² is—(C₁-C₅₀)hydrocarbylene-OH. The demulsifier can include an alkoxylatedalcohol surfactant that is a (C₁-C₅₀)hydrocarbyl-OH having a—((C₂-C₃)alkylene-O)_(n)—H group on the —OH group, wherein n is about 1to about 100. The demulsifier composition can also include anamine-oxide surfactant. At each occurrence the (C₁-C₅₀)hydrocarbyl and(C₁-C₅₀)hydrocarbylene are substituted or unsubstituted and areindependently selected.

EXAMPLES

Various embodiments of the present invention can be better understood byreference to the following Examples, which are offered by way ofillustration. The present invention is not limited to the Examples givenherein.

Example 1. Formation of Sample Compositions

Two sample compositions were formed, Sample 1 and Sample 2, according toTable 1. Sample 1 was a microemulsion with an inner oil phase and anouter water phase, with the droplets of the inner oil phase having asize of 10 nm to 150 nm. Sample 2 has the same composition as Sample 1,but lacked the oil phase and was not an emulsion.

TABLE 1 Ingredients Category Sample 1 Sample 2 De-ionized water Water 30%  60% Escaid ™ Oil  30%  0% PathFrac ™ fluid iso-propanol Co-solvent 10%  10% Tergitol ™ 15-S-7 Secondary alcohol  10%  10% surfactantethyoxylate Amadol ® 511 Alkanolamide  10%  10% surfactant Ammonyx ®LMDO Amine-oxide  10%  10% surfactant Total 100% 100%

Example 2, Comparison of Properties of Sample Compositions and OtherDemulsifier Compositions

Properties of Sample 1 from Example 1, GasPerm 1000™ surfactant blend,and LoSurf-300D™ surfactant blend were compared.

RockPerm℠ Gas Values.

Rock Perm™ Gas values were determined by performing the followingprocedure. A plastic column was filled with sand. The dry weight of thesand was obtained. Formation water (8 mL, 7% KCl) was added, and gravitywas allowed to pull the formation water into the column. Demulsifiercomposition (12 mL) was added, and gravity was allowed to pull thedemulsifier composition into the column. The wet weight of the columnwas obtained. Pore volume was calculated using the expression: porevolume=wet weight of column−dry weight of column (assuming the densityof water). Positive gas pressure was placed on the top of the column.All of the treatment fluid that was displaced from the column wascaptured in a flask over a tared balance. The wt % fluid displaced iscalculated based on the weight of the fluid displaced from the column.The pressure across the sandpack was monitored. The RockPerm℠ Gas valuewas calculated as: wt % fluid displaced/maximum pressure measured(psig).

RockPerm℠ Values.

RockPerm℠ values were determined by performing the following procedure.A glass column was provided. The hosecock (stopper) on the column wasclosed. Formation water (10 mL, 7% KCl) was added to the column.Proppant (100 mesh sand, 10 g) was slowly added to the formation water.The column was vibrated for 10 seconds to pack the sand. The hosecockwas opened and the formation water was allowed to flow until themeniscus reached the top of the sand bed. The pore volume (PV) of thesand bed was measured by measuring the volume of water in the sand bed.The proppant was treated with 3 pore volumes (3 PV) of a brokenfracturing fluid (7% KCl) containing 2 gpt (gallons per thousandgallons) of the demulsifier composition. The broken fracturing fluid wasdrained from the column until the meniscus reached the top of the sandbed. The hosecock of the column was closed. Formation oil was added tothe 15 mL mark (wherein the 0 mL mark is at the bottom of the column).The hosecock was opened, and the fracturing fluid displaced by the oilwas collected over time. The experiment was stopped when the formationoil broke through the sand bed or at the 2 h mark, whichever happenedfirst. The time the oil broke through was called the breakthrough time(BTT). The weight of the fracturing fluid displaced at the BTT or at the2 h mark (if the oil did not breakthrough) was measured. The RockPerm℠Value (RPV) was estimated as RPV=(weight of fluid displaced (g)/BTT(h))*(weight of fluid displaced (g)/PV (mL)).

Emulsion Break Test.

The emulsion break test was performed by performing the followingprocedure. Fracturing fluid (5 mL) was added to a graduated cylinder.The fracturing fluid was spiked with 2 gal/1000 gal of surfactant, thecylinder was capped, and the cylinder was inverted. Formation oil (5 mL)was carefully added on top of the fluid. The cylinder was re-capped andwas inverted 10 times. The cylinder was set on a lab bench and a timerwas started. The volume of the separated fluid was recorded at 1, 5, and10 minutes at ambient temperature. If 100% separation was not achieved,the sample was placed at 180° F. (82.2° C.) and the volume of theseparated fluid was recorded at 1, 5, and 10 minutes at the elevatedtemperature.

The measured properties of Sample 1 from Example 1, GasPerm 1000™surfactant blend, and LoSurf-300D™ surfactant blend are shown in Table2.

TABLE 2 GasPerm 1000 ™ LoSurf-300D ™ Ingredients Sample 1 Sample 2surfactant blend surfactant blend Type Microemulsion ConventionalMicroemulsion Conventional (non- (non-emulsion) emulsion) StabilityStable Stable Stable Stable Solubility in 7% KCl Slightly insolubleSlightly Stable Slightly insoluble insoluble High temperature StableStable Stable Stable stability (93° C.) Low temperature Stable StableStable Stable stability (<−10° C.) RockPerm ℠ Gas 80 Not 50 60 (RPG, 7%KCl) measured RockPerm ℠ Value 61.54 32.6  2 20 (RPV, 7% KCl) Emulsionbreak <5 min at rt Not >10 min at rt; breaks <5 min at rt test, H₂Omeasured at 93° C. Emulsion break <5 min at rt Not >10 min at rt; breaks<5 min at rt test, 7% KCl measured at 93° C.

FIGS. 3A-C illustrate photographs of the emulsion break test performedon Sample 1 from Example 1 at room temperature at 1 minute (FIG. 3A), 5minutes (FIG. 3B), and at 10 minutes (FIG. 3C).

FIGS. 4A-C illustrate photographs of the emulsion break test performedon Sample 1 from Example 1 at 93° C. at 1 minute (FIG. 4A), 5 minutes(FIG. 4B), and at 10 minutes (FIG. 4C).

FIGS. 5A-C illustrate photographs of the emulsion break test performedon Sample 2 from Example 1 at room temperature at 1 minute (FIG. 5A), 5minutes (FIG. 5B), and at 10 minutes (FIG. 5C).

FIGS. 6A-C illustrate photographs of the emulsion break test performedon Sample 2 from Example 1 at 93° C. at 1 minute (FIG. 6A), 5 minutes(FIG. 6B), and at 10 minutes (FIG. 6C).

FIGS. 7A-C illustrate photographs of the emulsion break test performedon Sample 1 from Example 1 at room temperature 7% KCl at 1 minute (FIG.7A), 5 minutes (FIG. 7B), and at 10 minutes (FIG. 7C).

FIGS. 8A-C illustrate photographs of the emulsion break test performedon Sample 2 from Example 1 at room temperature using 7% KCl at 1 minute(FIG. 8A), 5 minutes (FIG. 8B), and at 10 minutes (FIG. 8C).

The terms and expressions that have been employed are used as terms ofdescription and not of limitation, and there is no intention in the useof such terms and expressions of excluding any equivalents of thefeatures shown and described or portions thereof, but it is recognizedthat various modifications are possible within the scope of theembodiments of the present invention. Thus, it should be understood thatalthough the present invention has been specifically disclosed byspecific embodiments and optional features, modification and variationof the concepts herein disclosed may be resorted to by those of ordinaryskill in the art, and that such modifications and variations areconsidered to be within the scope of embodiments of the presentinvention.

Additional Embodiments

The following exemplary embodiments are provided, the numbering of whichis not to be construed as designating levels of importance:

Embodiment 1 provides a method of treating a subterranean formation, themethod comprising:

placing in the subterranean formation a demulsifier compositioncomprising:

-   -   an alkanolamide surfactant that is a (C₁-C₅₀)hydrocarbyl amide        having groups R¹ and R² substituted on the amide nitrogen,        wherein R¹ and R² are each independently selected from the group        consisting of —H, —(C₁-C₅₀)hydrocarbyl, and        —(C₁-C₅₀)hydrocarbylene-OH, wherein at least one of R¹ and R² is        —(C₁-C₅₀)hydrocarbylene-OH;    -   an alkoxylated alcohol surfactant that is a        (C₁-C₅₀)hydrocarbyl-OH having a —((C₂-C₃)alkylene-O)_(n)—H group        on the —OH group, wherein n is about 1 to about 100; and    -   an amine-oxide surfactant;    -   wherein at each occurrence the (C₁-C₅₀)hydrocarbyl and        (C₁-C₅₀)hydrocarbylene are substituted or unsubstituted and are        independently selected.

Embodiment 2 provides the method of Embodiment 1, wherein a subterraneantreatment fluid comprises the demulsifier composition, wherein thesubterranean treatment fluid is a stimulation fluid, a hydraulicfracturing fluid, a drilling fluid, a spotting fluid, a clean-up fluid,a completion fluid, a remedial treatment fluid, an abandonment fluid, apill, an acidizing fluid, a cementing fluid, a packer fluid, a loggingfluid, or a combination thereof.

Embodiment 3 provides the method of any one of Embodiments 1-2, whereinthe method comprises performing a subterranean formation treatmentoperation in the subterranean formation comprising hydraulic fracturing,stimulation, drilling, spotting, clean-up, completion, remedialtreatment, abandonment, acidizing, cementing, packing, logging, or acombination thereof.

Embodiment 4 provides the method of any one of Embodiments 1-3, whereina subterranean treatment fluid comprises the demulsifier composition,wherein the subterranean treatment fluid comprises a hydraulicfracturing fluid.

Embodiment 5 provides the method of any one of Embodiments 1-4, whereinthe method comprises hydraulically fracturing the subterranean formationwith the demulsifier composition or with a subterranean treatment fluidcomprising the demulsifier composition.

Embodiment 6 provides the method of any one of Embodiments 1-5, whereinthe method further comprises obtaining or providing the demulsifiercomposition, wherein the obtaining or providing of the demulsifiercomposition occurs above-surface.

Embodiment 7 provides the method of any one of Embodiments 1-6, whereinthe method further comprises obtaining or providing the demulsifiercomposition, wherein the obtaining or providing of the demulsifiercomposition occurs in the subterranean formation.

Embodiment 8 provides the method of any one of Embodiments 1-7, furthercomprising reducing or eliminating an emulsion in the subterraneanformation

Embodiment 9 provides the method of any one of Embodiments 1-8, furthercomprising reducing or eliminating formation of an emulsion in thesubterranean formation.

Embodiment 10 provides the method of any one of Embodiments 1-9, whereinthe demulsifier composition further comprises a water phase.

Embodiment 11 provides the method of Embodiment 10, wherein the water isabout 0.01 wt % to about 99.99 wt % of the demulsifier composition.

Embodiment 12 provides the method of any one of Embodiments 10-11,wherein the water is about 10 wt % to about 80 wt % of the demulsifiercomposition.

Embodiment 13 provides the method of any one of Embodiments 1-12,wherein the demulsifier composition further comprises an organicsolvent.

Embodiment 14 provides the method of Embodiment 13, wherein the organicsolvent is about 0.01 wt % to about 99.99 wt % of the demulsifiercomposition.

Embodiment 15 provides the method of any one of Embodiments 13-14,wherein the organic solvent is about 5 wt % to about 30 wt % of thedemulsifier composition.

Embodiment 16 provides the method of any one of Embodiments 13-15,wherein the organic solvent is a water-miscible organic solvent.

Embodiment 17 provides the method of any one of Embodiments 13-16,wherein the organic solvent is a substituted or unsubstituted(C₁-C₂₀)hydrocarbyl alcohol.

Embodiment 18 provides the method of any one of Embodiments 13-17,wherein the organic solvent is a (C₁-C₅)alkyl alcohol.

Embodiment 19 provides the method of any one of Embodiments 13-18,wherein the organic solvent is ethanol, iso-propanol, n-propanol,n-butanol, s-butanol, t-butanol, n-pentanol, a pentanol isomer, or acombination thereof.

Embodiment 20 provides the method of any one of Embodiments 1-19,wherein the demulsifier composition further comprises an oil phase.

Embodiment 21 provides the method of any one of Embodiments 1-20,wherein the oil phase is about 0.01 wt % to about 99.99 wt % of thedemulsifier composition.

Embodiment 22 provides the method of any one of Embodiments 1-21,wherein the oil phase is about 10 wt % to about 80 wt % of thedemulsifier composition.

Embodiment 23 provides the method of any one of Embodiments 1-22,wherein the oil phase comprises hydrotreated light petroleum distillateshaving a boiling point range greater than about 200° C. and less thanabout 250° C.

Embodiment 24 provides the method of any one of Embodiments 1-23,wherein the demulsifier composition comprises both an aqueous phase andan oil phase.

Embodiment 25 provides the method of Embodiment 24, wherein thedemulsifier composition comprises an emulsion comprising the aqueousphase and the oil phase.

Embodiment 26 provides the method of Embodiment 25, wherein the aqueousphase is the outer phase and the oil phase is the inner phase.

Embodiment 27 provides the method of any one of Embodiments 25-26,wherein the oil phase is the outer phase and the aqueous phase is theinner phase.

Embodiment 28 provides the method of any one of Embodiments 25-27,wherein the emulsion becomes unstable upon dilution with water.

Embodiment 29 provides the method of any one of Embodiments 25-28,wherein the emulsion is unstable at a concentration of 0.2 wt % inwater.

Embodiment 30 provides the method of any one of Embodiments 25-29,wherein the emulsion is unstable at a concentration of 0.2 wt % inbrine.

Embodiment 31 provides the method of any one of Embodiments 25-30,wherein the emulsion is unstable at a concentration of 0.2 wt % in watercomprising 7 wt % KCl.

Embodiment 32 provides the method of any one of Embodiments 25-31,wherein the emulsion is a microemulsion.

Embodiment 33 provides the method of any one of Embodiments 1-32,wherein the alkanolamide surfactant is about 1 wt % to about 90 wt % ofthe demulsifier composition.

Embodiment 34 provides the method of any one of Embodiments 1-33,wherein the alkanolamide surfactant is about 5 wt % to about 40 wt % ofthe demulsifier composition.

Embodiment 35 provides the method of any one of Embodiments 1-34,wherein the alkanolamide surfactant has the structure:

wherein R³ is the (C₁-C₅₀)hydrocarbyl group.

Embodiment 36 provides the method of Embodiment 35, wherein thealkanolamide surfactant is an alkanolamide of a tall oil fatty acid.

Embodiment 37 provides the method of any one of Embodiments 35-36,wherein the (C₁-C₅₀)hydrocarbyl groups and the—(C₁-C₅₀)hydrocarbylene-OH group of the alkanolamide surfactant areunsubstituted.

Embodiment 38 provides the method of any one of Embodiments 35-37,wherein R³ is a substituted or unsubstituted (C₁₂-C₂₅)hydrocarbyl.

Embodiment 39 provides the method of any one of Embodiments 35-38,wherein R³ is a substituted or unsubstituted (C₁₅-C₁₇)hydrocarbyl.

Embodiment 40 provides the method of any one of Embodiments 35-39, thealkanolamide surfactant is the alkanolamide of a tall oil fatty acidhaving the structure R³—C(O)—OH.

Embodiment 41 provides the method of any one of Embodiments 1-40,wherein the alkanolamide surfactant is a tall oil (C₁₆-C₁₈)fatty acidalkanolamide.

Embodiment 42 provides the method of any one of Embodiments 35-41,wherein both of R¹ and R² are independently —(C₁-C₅₀)hydrocarbylene-OH.

Embodiment 43 provides the method of any one of Embodiments 35-42,wherein one of R¹ and R² are independently —(C₁-C₅₀)hydrocarbylene-OH.

Embodiment 44 provides the method of any one of Embodiments 35-43,wherein R¹ and R² are independently selected from —H, substituted orunsubstituted (C₁-C₁₀)hydrocarbyl, and substituted or unsubstituted—(C₁-C₁₀)hydrocarbylene-OH.

Embodiment 45 provides the method of any one of Embodiments 35-44,wherein R¹ and R² are independently selected from —H, —(C₁-C₅)alkyl, and—(C₁-C₅)alkylene-OH.

Embodiment 46 provides the method of any one of Embodiments 35-45,wherein R¹ and R² are each —CH₂—CH₂—OH.

Embodiment 47 provides the method of any one of Embodiments 1-46,wherein the alkanolamide surfactant has the structure:

wherein R³ is a substituted or unsubstituted (C₁₅-C₁₇)hydrocarbyl of atall oil fatty acid having the structure R³—C(O)—OH, and

R¹ and R² are each —CH₂—CH₂—OH.

Embodiment 48 provides the method of any one of Embodiments 1-47,wherein the alkoxylated alcohol surfactant is about 1 wt % to about 90wt % of the demulsifier composition.

Embodiment 49 provides the method of any one of Embodiments 1-48,wherein the alkoxylated alcohol surfactant is about 5 wt % to about 40wt % of the demulsifier composition.

Embodiment 50 provides the method of any one of Embodiments 1-49,wherein the alkoxylated alcohol surfactant has the structure:

R⁴—O—R⁵

wherein

-   -   R⁴ is the (C₁-C₅₀)hydrocarbyl group, and    -   R⁵ is the —((C₂-C₃)alkylene-O)_(n)—H group.

Embodiment 51 provides the method of Embodiment 50, wherein the alcoholis a secondary alcohol.

Embodiment 52 provides the method of any one of Embodiments 50-51,wherein the oxygen atom is bound to R⁴ at a carbon atom having two othercarbon atoms bound thereto in R⁴.

Embodiment 53 provides the method of any one of Embodiments 50-52,wherein R⁴ is unsubstituted aside from the alcohol.

Embodiment 54 provides the method of any one of Embodiments 50-53,wherein R⁴ is a (C₅-C₂₅)hydrocarbyl group.

Embodiment 55 provides the method of any one of Embodiments 50-54,wherein R⁴ is a (C₁₀-C₂₀)hydrocarbyl group.

Embodiment 56 provides the method of any one of Embodiments 50-55,wherein R⁴ is a (C₁₅)hydrocarbyl group.

Embodiment 57 provides the method of any one of Embodiments 50-56,wherein R⁵ is a -(ethylene-O)_(n)—H group.

Embodiment 58 provides the method of any one of Embodiments 50-57,wherein n is about 2 to about 20.

Embodiment 59 provides the method of any one of Embodiments 50-58,wherein n is about 5 to about 10.

Embodiment 60 provides the method of any one of Embodiments 50-59,wherein n is about 7.

Embodiment 61 provides the method of any one of Embodiments 50-60,wherein R⁵ is a -(ethylene-O)₇—H group.

Embodiment 62 provides the method of any one of Embodiments 1-61,wherein the alkoxylated alcohol surfactant is a (C₁₅)hydrocarboncomprising a secondary alcohol group, wherein the (C₁₅)hydrocarbon isotherwise unsubstituted, wherein the secondary alcohol group comprises a—(CH₂—CH₂—O)₇—H group thereon.

Embodiment 63 provides the method of any one of Embodiments 1-62,wherein the amine-oxide surfactant is about 0.01 wt % to about 90 wt %of the demulsifier composition.

Embodiment 64 provides the method of any one of Embodiments 1-63,wherein the amine-oxide surfactant is about 0.01 wt % to about 20 wt %of the demulsifier composition.

Embodiment 65 provides the method of any one of Embodiments 1-64,wherein the amine-oxide surfactant has the structure:

wherein

-   -   R⁶ is substituted or unsubstituted (C₁-C₅₀)hydrocarbyl,    -   R⁷ is substituted or unsubstituted (C₁-C₂₀)hydrocarbylene, and    -   at each occurrence, R⁸ is independently substituted or        unsubstituted (C₁-C₂₀)hydrocarbyl.

Embodiment 66 provides the method of Embodiment 65, wherein R⁶ is(C₅-C₃₀)hydrocarbyl.

Embodiment 67 provides the method of any one of Embodiments 65-66,wherein R⁶ is (C₅-C₂₀)alkyl.

Embodiment 68 provides the method of any one of Embodiments 65-67,wherein R⁶ is (C₁₁-C₁₃)alkyl.

Embodiment 69 provides the method of any one of Embodiments 65-68,wherein R⁷ is a (C₁-C₁₀)hydrocarbylene.

Embodiment 70 provides the method of any one of Embodiments 65-69,wherein R⁷ is a (C₁-C₅)alkylene.

Embodiment 71 provides the method of any one of Embodiments 65-70,wherein R⁷ is propylene.

Embodiment 72 provides the method of any one of Embodiments 65-71,wherein R⁸ is (C₁-C₅)alkyl.

Embodiment 73 provides the method of any one of Embodiments 65-72,wherein at each occurrence, R⁸ is methyl.

Embodiment 74 provides the method of any one of Embodiments 1-73,wherein the amine-oxide surfactant has the structure:

Embodiment 75 provides the method of any one of Embodiments 1-74,wherein the amine-oxide surfactant has the structure:

Embodiment 76 provides the method of any one of Embodiments 1-75,wherein the amine-oxide surfactant has the structure:

wherein the demulsifier composition further comprises anotheramine-oxide surfactant having the structure:

Embodiment 77 provides the method of any one of Embodiments 1-76,wherein the demulsifier composition further comprises base, acid,alcohol or polyol, cellulose, starch, alkalinity control agent, aciditycontrol agent, density control agent, density modifier, emulsifier,dispersant, polymeric stabilizer, polyacrylamide, polymer or combinationof polymers, antioxidant, heat stabilizer, foam control agent, solvent,diluent, plasticizer, filler or inorganic particle, pigment, dye,precipitating agent, oil-wetting agent, set retarding additive,corrosion inhibitor, gas, weight reducing additive, heavy-weightadditive, lost circulation material, filtration control additive, salt,fiber, thixotropic additive, breaker, crosslinker, gas, rheologymodifier, curing accelerator, curing retarder, pH modifier, chelatingagent, scale inhibitor, enzyme, resin, water control material,disproportionate permeability modifier, relative permeability modifier,polymer, oxidizer, a marker, or a combination thereof.

Embodiment 78 provides the method of any one of Embodiments 1-77,wherein the placing of the demulsifier composition in the subterraneanformation comprises fracturing at least part of the subterraneanformation to form at least one subterranean fracture.

Embodiment 79 provides the method of any one of Embodiments 1-78,wherein the demulsifier composition further comprises a proppant, aresin-coated proppant, or a combination thereof.

Embodiment 80 provides the method of any one of Embodiments 1-79,wherein the placing of the demulsifier composition in the subterraneanformation comprises pumping the demulsifier composition through atubular disposed in a wellbore and into the subterranean formation.

Embodiment 81 provides a system for performing the method of any one ofEmbodiments 1-80, the system comprising:

a tubular disposed in the subterranean formation; and

a pump configured to pump the demulsifier composition in thesubterranean formation through the tubular.

Embodiment 82 provides the method of any one of Embodiments 1-80,further comprising combining the demulsifier composition with an aqueousor oil-based fluid comprising a drilling fluid, stimulation fluid,fracturing fluid, spotting fluid, clean-up fluid, completion fluid,remedial treatment fluid, abandonment fluid, pill, acidizing fluid,cementing fluid, packer fluid, logging fluid, or a combination thereof,to form a mixture, wherein the placing the demulsifier composition inthe subterranean formation comprises placing the mixture in thesubterranean formation.

Embodiment 83 provides the method of any one of Embodiments 1-80 or 82,wherein at least one of prior to, during, and after the placing of thedemulsifier composition in the subterranean formation, the demulsifiercomposition is used in the subterranean formation, at least one of aloneand in combination with other materials, as a drilling fluid,stimulation fluid, fracturing fluid, spotting fluid, clean-up fluid,completion fluid, remedial treatment fluid, abandonment fluid, pill,acidizing fluid, cementing fluid, packer fluid, logging fluid, or acombination thereof.

Embodiment 84 provides a method of treating a subterranean formation,the method comprising:

-   -   placing in the subterranean formation a demulsifier composition        comprising    -   an aqueous phase;    -   an oil phase, wherein the demulsifier composition comprises an        emulsion comprising the aqueous phase and the oil phase;    -   an alkanolamide surfactant that has the structure:

-   -   -   wherein R³ is a substituted or unsubstituted            (C₁₂-C₂₅)hydrocarbyl of a tall oil fatty acid having the            structure R³—C(O)—OH, and        -   R¹ and R² are each independently —(C₁-C₁₀)alkylene-OH;

    -   an alkoxylated alcohol surfactant that is a (C₁₀-C₂₀)hydrocarbon        comprising a secondary alcohol group, wherein the        (C₁₀-C₂₀)hydrocarbon is otherwise unsubstituted, wherein the        secondary alcohol group comprises a —(CH₂—CH₂—O)₅₋₁₀—H group        thereon; and

    -   an amine-oxide surfactant having the structure:

-   -   wherein        -   R⁶ is (C₁₁-C₁₃)alkyl,        -   R⁷ is (C₁-C₅)alkylene, and        -   at each occurrence, R⁸ is independently (C₁-C₅)alkyl.

Embodiment 85 provides a method of treating a subterranean formation,the method comprising:

placing in the subterranean formation a demulsifier compositioncomprising

-   -   an aqueous phase that is about 10 wt % to about 80 wt % of the        demulsifier composition;    -   an oil phase that is about 10 wt % to about 80 wt % of the        demulsifier composition, wherein the demulsifier composition        comprises an emulsion comprising the aqueous phase and the oil        phase;    -   a (C₁-C₅)alkyl alcohol that is about 5 wt % to about 30 wt % of        the demulsifier composition;    -   an alkanolamide surfactant that is about 5 wt % to about 40 wt %        of the demulsifier composition, wherein the alkanolamide        surfactant has the structure:

-   -   -   wherein R³ is a substituted or unsubstituted            (C₁₅-C₁₇)hydrocarbyl of a tall oil fatty acid having the            structure R³—C(O)—OH, and        -   R¹ and R² are each —CH₂—CH₂—OH;

    -   an alkoxylated alcohol surfactant that is about 5 wt % to about        40 wt % of the demulsifier composition, wherein the alkoxylated        alcohol surfactant is a (C₁₅)hydrocarbon comprising a secondary        alcohol group, wherein the (C₁₅)hydrocarbon is otherwise        unsubstituted, wherein the secondary alcohol group comprises a        —(CH₂—CH₂—O)₇—H group thereon;

    -   an amine-oxide surfactant that is about 0.01 wt % to about 20 wt        % of the demulsifier composition, wherein the amine-oxide        surfactant has the structure:

-   -    and    -   an amine-oxide surfactant that is about 0.01 wt % to about 20 wt        % of the demulsifier composition, wherein the amine-oxide        surfactant has the structure:

Embodiment 86 provides a method of treating produced petroleumcomprising an emulsion, the method comprising:

contacting the produced petroleum comprising the emulsion with ademulsifier composition to reduce or eliminate the emulsion, thedemulsifier composition comprising

-   -   an alkanolamide surfactant that is a (C₁-C₅₀)hydrocarbyl amide        having groups R¹ and R² substituted on the amide nitrogen,        wherein R¹ and R² are each independently selected from the group        consisting of —H, —(C₁-C₅₀)hydrocarbyl, and        —(C₁-C₅₀)hydrocarbylene-OH, wherein at least one of R¹ and R² is        —(C₁-C₅₀)hydrocarbylene-OH;    -   an alkoxylated alcohol surfactant that is a        (C₁-C₅₀)hydrocarbyl-OH having a —((C₂-C₃)alkylene-O)_(n)—H group        on the —OH group, wherein n is about 1 to about 100; and    -   an amine-oxide surfactant;    -   wherein at each occurrence the (C₁-C₅₀)hydrocarbyl and        (C₁-C₅₀)hydrocarbylene are substituted or unsubstituted and are        independently selected.

Embodiment 87 provides a system comprising:

a tubular disposed in a subterranean formation; and

a pump configured to pump a demulsifier composition in the subterraneanformation through the tubular, wherein the demulsifier compositioncomprises

-   -   an alkanolamide surfactant that is a (C₁-C₅₀)hydrocarbyl amide        having groups R¹ and R² substituted on the amide nitrogen,        wherein R¹ and R² are each independently selected from the group        consisting of —H, —(C₁-C₅₀)hydrocarbyl, and        —(C₁-C₅₀)hydrocarbylene-OH, wherein at least one of R¹ and R² is        —(C₁-C₅₀)hydrocarbylene-OH;    -   an alkoxylated alcohol surfactant that is a        (C₁-C₅₀)hydrocarbyl-OH having a —((C₂-C₃)alkylene-O)_(n)—H group        on the —OH group, wherein n is about 1 to about 100; and    -   an amine-oxide surfactant;    -   wherein at each occurrence the (C₁-C₅₀)hydrocarbyl and        (C₁-C₅₀)hydrocarbylene are substituted or unsubstituted and are        independently selected.

Embodiment 88 provides a demulsifier composition comprising:

an alkanolamide surfactant that is a (C₁-C₅₀)hydrocarbyl amide havinggroups R¹ and R² substituted on the amide nitrogen, wherein R¹ and R²are each independently selected from the group consisting of —H,—(C₁-C₅₀)hydrocarbyl, and —(C₁-C₅₀)hydrocarbylene-OH, wherein at leastone of R¹ and R² is —(C₁-C₅₀)hydrocarbylene-OH;

an alkoxylated alcohol surfactant that is a (C₁-C₅₀)hydrocarbyl-OHhaving a —((C₂-C₃)alkylene-O)_(n)—H group on the —OH group, wherein n isabout 1 to about 100; and

an amine-oxide surfactant;

wherein at each occurrence the (C₁-C₅₀)hydrocarbyl and(C₁-C₅₀)hydrocarbylene are substituted or unsubstituted and areindependently selected.

Embodiment 89 provides a demulsifier composition comprising:

an aqueous phase;

an oil phase, wherein the demulsifier composition comprises an emulsioncomprising the aqueous phase and the oil phase;

an alkanolamide surfactant that has the structure:

-   -   wherein R³ is a substituted or unsubstituted        (C₁₂-C₂₅)hydrocarbyl of a tall oil fatty acid having the        structure R³—C(O)—OH, and    -   R¹ and R² are each independently —(C₁-C₁₀)alkylene-OH;

an alkoxylated alcohol surfactant that is a (C₁₀-C₂₀)hydrocarboncomprising a secondary alcohol group, wherein the (C₁₀-C₂₀)hydrocarbonis otherwise unsubstituted, wherein the secondary alcohol groupcomprises a —(CH₂—CH₂—O)₅₋₁₀—H group thereon; and

an amine-oxide surfactant having the structure:

wherein

-   -   R⁶ is (C₁₁-C₁₃)alkyl,    -   R⁷ is (C₁-C₅)alkylene, and    -   at each occurrence, R⁸ is independently (C₁-C₅)alkyl.

Embodiment 90 provides a demulsifier composition comprising:

an aqueous phase that is about 10 wt % to about 80 wt % of thedemulsifier composition;

an oil phase that is about 10 wt % to about 80 wt % of the demulsifiercomposition, wherein the demulsifier composition comprises an emulsioncomprising the aqueous phase and the oil phase;

a (C₁-C₅)alkyl alcohol that is about 5 wt % to about 30 wt % of thedemulsifier composition;

an alkanolamide surfactant that is about 5 wt % to about 40 wt % of thedemulsifier composition, wherein the alkanolamide surfactant has thestructure:

-   -   wherein R³ is a substituted or unsubstituted        (C₁₅-C₁₇)hydrocarbyl of a tall oil fatty acid having the        structure R³—C(O)—OH, and    -   R¹ and R² are each —CH₂—CH₂—OH;

an alkoxylated alcohol surfactant that is about 5 wt % to about 40 wt %of the demulsifier composition, wherein the alkoxylated alcoholsurfactant is a (C₁₅)hydrocarbon comprising a secondary alcohol group,wherein the (C₁₅)hydrocarbon is otherwise unsubstituted, wherein thesecondary alcohol group comprises a —(CH₂—CH₂—O)₇—H group thereon;

an amine-oxide surfactant that is about 0.01 wt % to about 20 wt % ofthe demulsifier composition, wherein the amine-oxide surfactant has thestructure:

and

an amine-oxide surfactant that is about 0.01 wt % to about 20 wt % ofthe demulsifier composition, wherein the amine-oxide surfactant has thestructure:

Embodiment 91 provides a method of preparing a demulsifier compositionfor treatment of a subterranean formation or of produced petroleumcomprising an emulsion, the method comprising:

forming a demulsifier composition comprising

-   -   an alkanolamide surfactant that is a (C₁-C₅₀)hydrocarbyl amide        having groups R¹ and R² substituted on the amide nitrogen,        wherein R¹ and R² are each independently selected from the group        consisting of —H, —(C₁-C₅₀)hydrocarbyl, and        —(C₁-C₅₀)hydrocarbylene-OH, wherein at least one of R¹ and R² is        —(C₁-C₅₀)hydrocarbylene-OH;    -   an alkoxylated alcohol surfactant that is a        (C₁-C₅₀)hydrocarbyl-OH having a —((C₂-C₃)alkylene-O)_(n)—H group        on the —OH group, wherein n is about 1 to about 100; and    -   an amine-oxide surfactant;    -   wherein at each occurrence the (C₁-C₅₀)hydrocarbyl and        (C₁-C₅₀)hydrocarbylene are substituted or unsubstituted and are        independently selected.

Embodiment 92 provides the demulsifier composition, method, or system ofany one or any combination of Embodiments 1-91 optionally configuredsuch that all elements or options recited are available to use or selectfrom.

What is claimed is:
 1. A method of treating a subterranean formation,the method comprising: placing in the subterranean formation ademulsifier composition comprising: a microemulsion comprising anaqueous phase and an oil phase; an alkanolamide surfactant that has thestructure:

wherein R³ is a substituted or unsubstituted (C₁₂-C₂₅)hydrocarbyl of atall oil fatty acid having the structure R³—C(O)—OH, and R¹ and R² areeach independently —(C₁-C₁₀)alkylene-OH; an alkoxylated alcoholsurfactant that is a (C₁₀-C₂₀)hydrocarbon comprising a secondary alcoholgroup, wherein the (C₁₀-C₂₀)hydrocarbon is otherwise unsubstituted,wherein the secondary alcohol group comprises a —(CH₂—CH₂—O)₅₋₁₀—H groupthereon; and an amine-oxide surfactant having the structure:

wherein R⁶ is (C₁₁-C₁₃)alkyl, R⁷ is (C₁-C₅)alkylene, and at eachoccurrence, R⁸ is independently (C₁-C₅)alkyl.
 2. The method of claim 1,wherein the method comprises hydraulically fracturing the subterraneanformation with the demulsifier composition or with a subterraneantreatment fluid comprising the demulsifier composition.
 3. The method ofclaim 1, further comprising reducing or eliminating an emulsion in thesubterranean formation, reducing or eliminating formation of an emulsionin the subterranean formation, or a combination thereof.
 4. The methodof claim 1, wherein the demulsifier composition further comprises anorganic solvent.
 5. The method of claim 1, wherein the alkanolamidesurfactant has the structure:

wherein R³ is a substituted or unsubstituted (C₁₅-C₁₇)hydrocarbyl of atall oil fatty acid having the structure R³—C(O)—OH, and R¹ and R² areeach —CH₂—CH₂—OH.
 6. The method of claim 1, wherein the alkoxylatedalcohol surfactant has the structure:R⁴—O—R⁵, wherein R⁴ is the (C₁₀-C₂₀)hydrocarbon, and R⁵ is the—(CH₂—CH₂—O)₅₋₁₀—H group.
 7. The method of claim 1, wherein thealkoxylated alcohol surfactant is a (C₁₅)hydrocarbon comprising asecondary alcohol group, wherein the (C₁₅)hydrocarbon is otherwiseunsubstituted, wherein the secondary alcohol group comprises a—(CH₂—CH₂—O)₇—H group thereon.
 8. The method of claim 1, wherein theamine-oxide surfactant has the structure:


9. The method of claim 1, wherein the amine-oxide surfactant has thestructure:


10. The method of claim 1, further comprising decreasing or eliminatinga water-in-crude oil emulsion in the subterranean formation with thedemulsifier composition.
 11. The method of claim 1, wherein upondilution in the subterranean formation the alkanolamide surfactantpartitions into a crude oil phase present in the subterranean formation;and wherein the undiluted microemulsion is stable at high temperaturebetween about 50° C. and about 300° C.
 12. The method of claim 1,wherein the microemulsion comprises droplets of an inner phase having asize of 0.01 microns to about 0.15 microns, wherein at least one of theoil phase and the aqueous phase is the inner phase.
 13. The method ofclaim 1, wherein the microemulsion is an oil-in-water microemulsion,wherein the aqueous phase is an outer phase of the oil-in-watermicroemulsion and wherein the oil phase is an inner phase of theoil-in-water microemulsion.
 14. The method of claim 13, furthercomprising decreasing or eliminating a water-in-crude oil emulsion inthe subterranean formation with the demulsifier composition.
 15. Themethod of claim 14, wherein upon dilution in the subterranean formationthe alkanolamide surfactant partitions into the crude oil phase,facilitating demulsification of the crude oil phase, and wherein theundiluted microemulsion is stable at a high temperature between about50° C. and about 300° C.
 16. The method of claim 15, wherein themicroemulsion comprises droplets of the inner oil phase having a size ofabout 0.01 microns to about 0.15 microns.
 17. The method of claim 1,wherein the microemulsion is stable at a high temperature between about50° C. and about 300° C.
 18. The method of claim 1, wherein themicroemulsion is unstable when diluted to a concentration of about 0.2wt % in water or brine.
 19. The method of claim 1, wherein themicroemulsion is stable in the presence of a total dissolved solidslevel of about 0 mg/L to about 250,000 mg/L.
 20. The method of claim 1,wherein the microemulsion has a freezing point below about 10° C.